When it was warm enough and he was at liberty to do so, Harry liked to take his lunch on the Southsea Commons. The sea breeze through the elms and the plaintive cries of the gulls circling the bay made for pleasant companions as he ate.
Harry unwrapped the grease paper from his sandwich. Word had come down that morning that a new posting had been found for him. Something very hush-hush. No location given, though his commander had hinted that he wouldn't be going abroad. Harry chewed reflectively. He had signed on with the Navy to do his duty and maybe see a bit of the world, but thus far, the only bit of the world he'd seen during his commission was the part which fell within the city limits of Portsmouth.
A few gulls gathered on the grass in front of Harry's bench, bobbing their heads up and down and squawking. Harry absentmindedly ripped off a bit of bread and tossed it towards them.
"Now, don't fight over it old chaps," he said. Being gulls, they did. One particularly large bird with a distinctive black splotch on its wing won the battle and let out a triumphant call.
Harry wondered where he was about to be sent off to. A different base? But then, why the secrecy? Was he going to be assigned to some kind of proto-type vessel? The large gull took advantage of Harry's distraction to hop onto the bench and brazenly grab the rest of the sandwich.
"I say!" Harry jumped to his feet. The gull fluttered away with an alarmed screech. The rest of the beggars took to the air to follow it. Harry watched the procession, and his lunch, fly away towards the bay.
"Do you say?" a sonorous voice queried.
Harry jumped slightly. A very tall man wearing a floppy hat and a long, multi-coloured scarf most unsuited to the weather (most unsuited to any weather, really) was standing very close to the left side of the bench. The man grinned broadly and extended a white paper bag.
Caught off-guard, Harry took one of the proffered sweets and examined it carefully.
"Better eat it quick, Harry," the man said. He looked conspiratorially towards the bay and whispered, "I think they might be coming back for seconds, and I shouldn't want to be standing around when they do."
Harry cautiously bit into the jelly baby. "Do we know each other?"
The man stretched out his arms in an expansive shrug. "Do we?"
"You know my name, but I can't seem to place yours. Sorry about that, old chap, people do tend to come and go a far bit in my line of work."
"I am generally known as 'the Doctor'," the man said. His smile was frighteningly toothy. "Have you been hit on the head, Harry? Possessed by an alien entity intent on destroying the Earth? Cloned?"
"Not that I know of," said Harry. The Doctor responded by pulling what looked like an otoscope out of his pocket and waving it over Harry. The tool buzzed.
"Are you sure you're feeling all right?" Harry asked, taking a step back from the whirling instrument. "It is rather warm out today, and in that get-up you're risking heatstroke. It can cause confusion…"
"Cloned!" the Doctor shouted. Harry flinched. "It makes perfect sense. They haven't even got the hair right! Tell me, who are you, and what have you done with the real Harry Sullivan?"
"Now see here," Harry said, feeling both affronted by the man's rudeness and concerned about his state of mind. "I don't know what you're banging on about with clones and the like, but I am the real Harry Sullivan."
"But of course, a clone would say the same, and that's the trouble, isn't it?"
"Is it?" asked Harry.
"Of course, I could be wrong, perhaps you aren't a clone. Perhaps you're a mimic, or a wax dummy, or an Auton, or a brain washed sailor living inside a miniscope. One never knows around these parts." The Doctor examined his buzzing tool, frowned, thumped it against the back of his arm, and then grinned. He seemed to grin rather a lot. "Ah — Ah yes, I see."
The Doctor reached out and straightened Harry's uniform. "My apologies, Harry. I seem to have mistaken you for someone else. You look very similar and have the same name, but you won't be the same person for another year or so. I recommend using that time to grow out your hair a bit. I'll just be moving along now — ah." The Doctor turned to leave, and then stopped, facing towards the bay. "I've tarried too long. They've returned."
"The Grawska," the Doctor said gravely, raising his arm to the sky.
A grey-and-white swarm of seagulls was flocking towards them. The birds were dense enough to block out the sky. Their shrill cries were getting louder by the minute. They sounded hungry.
"I've never seen that many gulls flying together," Harry said.
"No, you haven't," the Doctor said, "And you never will. Those aren't birds, Harry, they're parasitical alien mimics intent on taking over this planet and stripping it of resources."
"What can we do about it?" asked Harry. The Doctor might well have escaped from somewhere, but the flock of not-gulls had begun to murmurate into odd, menacing spirals. The sounds of their calls was starting to hurt Harry's ears. He doubted they were aliens, but they were unnatural. Other people on the commons — picnickers, truant school children, mothers with prams, soldiers on break — had stopped their activities to stare at the swarm.
"We can run," said the Doctor.
"But all of these people!" said Harry, "We can't just leave them!"
"Very noble, Harry, but the Grawska will attack us first."
"Why should they do that?"
"Because we represent a known threat — and a solution to that threat in the same package. Paradox, Harry, if they kill you, I will vanish, and they will be free to commence their invasion."
"I don't follow."
"I can see you don't, but never mind that. This way!"
The Doctor started to run. Harry followed him. Wing beats and shrill cries filled the air. The swarm of gulls thickened above them. A column of birds appeared out of the main mass. It looked more like a dark tentacle than a collection of gulls. The column stretched towards them.
"Wrong way!" Harry shouted. The Doctor was heading towards the Royal Garrison Church, but the commons were fenced in that direction with no exit to the main path, and the unroofed church would provide no shelter from an airborne threat.
"What?" the Doctor hollered over his shoulder. The sound of the flock made communication impossible. Harry chanced a look back over his own shoulder. Turning back was impossible.
The Doctor reached the dead end and attempted to make the climb, but the not-birds, the Grawska, were everywhere. Harry watched the Doctor swinging at them with the ends of his scarf. Then he felt sharp claws digging into the back of his neck. He whirled, punching at the creature, but it fluttered back to a safe distance, staring at him with expressionless, beady eyes. Then it attacked again. They all attacked.
The Doctor pulled out his otoscope-looking tool (though, Harry had sincere doubts that the instrument had anything to do with ear examinations, or that "the Doctor" was anything of the sort) and waved it wildly back and forth. The tool let out a piercingly shrill noise. Harry slammed his hands of his ears to defend them. The flock momentarily retreated, enough for Harry, still covering his ears, to make his way to the Doctor's side, but then a single Grawska burst from the flock and knocked the tool from the Doctor's hand.
The alien landed on the green in front of them, just out of reach, the tool clutched in its beak. It cocked its head at Harry, black eyes glittering maliciously.
"You bally blighter," Harry said, recognizing the black splotch on the alien bird's side. "I fed you!"
"Not the best way to repay a favour, I agree," the Doctor said, clutching at his wrist. The creature's beak had left a nasty cut. Several more Grawska landed beside the one with the black splotch. The rest continued circling overhead. Harry had the nasty feeling that they were gloating.
"Can we bargain with them?" Harry asked.
"We could, but they would still kill us and devastate the Earth," the Doctor said.
"Then what can we do?"
"Us? Not terribly much, I'm afraid. But cheer up, Harry, I have faith that you'll come up with something."
Harry and Sarah-Jane were on the other side of the commons when the flock began its attack. They'd discovered the aliens' vessel beneath Southsea Castle and managed to salvage a bit of tech from the engine room as the Doctor had instructed. In the clear light of the open field, Sarah was busy examining their acquisition. It looked like a grey-painted cricket ball encased in wires and flashing lights.
Harry, meanwhile, was wandering around at a bit of a loss.
"You know, I used to take lunch down here every day when I could, back when I worked at the base."
"Harry, I'm busy," Sarah complained, poking at various bits and wires.
"Sorry, old thing, just a bit of nostalgia. He kicked at the grass, hands in pockets. Then he caught sight of the murmuration."That's odd."
Sarah looked up, and Harry recognized the surly look which meant she was about to bother him for being too old fashioned for her taste, but the look dropped away as soon as she caught sight of the flock. Sarah sprung to her feet, shouting. "It's the gathering! Just like the Doctor said!" She slung the tech into her bag and started running towards the flock. "Come on Harry!"
"Steady on, old girl, do you have a plan?"
Sarah slowed and looked back at Harry like he was a small child. "The Doctor said that once we'd found a bit of the Grawska ship, and slotted it into his machine it would find the right frequency to destroy the flock."
"Then shouldn't you be activating it?" Harry asked. "I might be wrong, but it sounded like the Doctor's gadget had a wide range and it seems a bit unduly risky to rush in without it turned on."
"And you would know?" Sarah-Jane asked.
"Well, it's worth a try, isn't it?"
Sarah-Jane huffed, but acquiesced. She slowed down and opened her bag, taking out the section of alien ship and the Doctor's machine. There didn't seem to be any logical way to fit the two together.
"It's a bit square peg, round hole, isn't it?" Harry asked.
Sarah-Jane picked up the bit of Grawska tech with one hand. She held the Doctor's machine, a slim metal wafer studded with gears and antennae, in the other. She looked from one to the other. Then bashed them together. There was a flash of light and a puff of smoke. Sarah-Jane yelped.
"I say!" said Harry. "Are you all right, old thing?"
The smoke cleared to reveal Sarah-Jane sitting in a pile of smoking wires sucking at her slightly singed fingers. "It was just a shock, Harry. Look!" She pointed to where the flock had been. "It worked!"
"Good job that," said Harry, looking at the wreckage. "I don't think we would've got a second chance with your methods. I suppose we still ought to get over there and see if there's anyone needing help."
It took a good few minutes to cross the commons. Harry and Sarah-Jane didn't find any casualties from the near-invasion until they reached the church and found the Doctor sitting with his back against a fence and a navy man passed out in his lap. The Doctor looked up at Harry and Sarah-Jane with his trademark broad grin.
"Shhhhh," he said. "You don't want to wake him, not after the bother I went through getting him to sleep."
"But that's —" Sarah-Jane started.
"Yes," the Doctor agreed, "it is."
Sarah-Jane looked from the downed man to Harry and then giggled.
"What?" Harry asked.
"I can't help it. You look strange with your sideburns gone."
Harry touched them, slightly embarrassed. "I should probably examine him, make certain he isn't injured…"
"Whatever for?" asked the Doctor, disentangling the young, unconscious Harry from his lap so that he could stand. "How do you feel?"
"Fine?" Harry said.
"Good. That means he's fine, and will continue to be fine, so long as you don't do anything stupid, like touching him."
"I don't remember any of this," said Harry.
"You wouldn't. I repressed the memories. Would you like them back?"
"I should think so!" said Harry.
"Well, remind me to get around to that," said the Doctor striding away from them both towards where they'd left the TARDIS. "There's several other things that need attending to first."
"What sort of other things?" asked Sarah.
"The message from the Brigadier, for one, the Earth is in danger!"
"Wait just a moment," said Harry, walking up beside the Doctor, "I thought this was the threat that the Brigadier was talking about."
"Obviously not. Your younger self over there hasn't met myself or Sarah yet, which means that the Brigadier doesn't have the space-time telegraph yet, which means that whatever menace he requires our assistance with is still on-going."
"So this was an entirely different invasion!" Sarah-Jane said.
"Yes, funny isn't it? Come along Sarah, come along Harry, we have an appointment to keep!"