You're about as helpful as a sack of wet mice. Darn it, now I want to write something where Ianto discovers just exactly how unhelpful a sack of wet mice is! *headdesk*

Asking John to look after Jack would be a phenomenally bad idea, because John would drag Jack back down to what he'd once been, all the progress he'd made would be lost. The Doctor would be better because at least Jack would try to live up to his mentor's ideals.

Finding what they're looking for is proving complicated. Hope they find it soon so they can go and rescue Jack!