The Doctor wasn’t expecting to run into his old friend and travelling companion, not right now and certainly not like this, in the storeroom of a school. In a way though, it isn’t really strange; over the centuries he’s become accustomed to expecting the unexpected, and for once the surprise is a pleasant one.
Sarah Jane looks amazing. She’s older of course, but she’s still the same vibrant, intelligent, courageous woman he remembers from their many adventures together. It’s good to spend time with her again, but they’ve both moved on.
At least this time they get to say goodbye.