Flatlanders

Young theoretical physicist Mickey Haiku has fallen into Eden's trap. She is a much smarter scientist who is intent on saving her own dimension by destroying his. Unbeknownst to either, beings from several yet higher dimensions have their own strategies. This sends the mixed-up pawns off on a wild odyssey through a dozen weird, twisted dimensions. As if this hyper-dimensional odyssey isn't challenging enough for Mickey, he has the additional difficulty of embarking on this whacko tour as a (pregnant!) female.
Which means Eden is stuck in Mickey's body. The two are soon forced to cooperate since each holds the other's body hostage. The strangest relationship this side of the 11th dimension develops between the two.