Padma
I don't read the sort of fiction that might treat tarot as a plot feature, but I did once read several that were clearly based on tarot and pathworking: Roger Zelazny's old Amber sci-fi/fantasy series. Each of the nine Princes of Amber had his own private universe, and each one had a Trump card that could open a pan-dimensional doorway so he could travel the paths between the universes and drop in on the others (where he wasn't always welcome). They used their Trumps in much the same way that tarot Trumps are used for pathworking on the Tree of Life.
I LOVED that series! Great tale! I think the best part was as you say, they could use the cards as doorways to travel through. (really, seems the whole point with tarot, doesn't it?) There were so many interesting layers of meaning in those books...
Andromeda Klein (Frank Portman). BRILLIANT.
YES.
Bone Dance by Emma Bull. The plot is outlined on a Celtic cross reading done by one of the characters, for the protagonist. Good book that looks at issues of gender, personal autonomy, and community. Cracking good story, too.
That sounds so interesting!