Torchwood’s latest brush with alien technology had resulted in Owen and Gwen being de-aged. It was unfortunate timing as Tosh was in Japan visiting her family.
“Look, we’ve seen things like this before,” Jack told them. “Tosh always makes comprehensive notes on all technology she studies. You’ve got nothing to worry about, I’ll soon have you both back to normal.”
Famous last words.
An hour later, Jack had managed to reverse the de-aging, resulting in two of his agents becoming old age pensioners somewhat prematurely.
“Oh well. At least they’re not kids anymore,” Ianto sighed. “Back to the drawing board.”