alternate history

What Mad Universe – A pulp fiction magazine editor is transported into another universe where an intergalactic war is going on, major cities are under complete blackouts, and he is being hunted for being an Arcturian spy.

House of Many Worlds – The watchers of the time-tracks send two agents into the melting pot of the cosmos. These two agents travel across several alternate histories in an effort to keep all of them from collapsing into chaos.