I'm looking for a novel I read in the 1990's, probably the mid-90s. In it, a boy comes from the future to take intelligent young people who will be beneficial in their time.
Due to misinformation, a girl he has come back to get is actually dying of some terminal illness, so he somehow takes another girl back instead.
There is a scene, at some point during the novel, where he is playing solitaire, and peeks at the cards hidden in the deck. The girl tells him that is cheating, but he says that that's how you play the game, thus creating a parallel to the situation of him taking the girl from the past to the future to help them.
Any help would be appreciated...