Seamus O'Hare, a bipolar, obsessive compulsive, germaphobe, falls head-over-heals for a delusional schizophrenic, Bonnie Allen, in a mental hospital. Over time, the two leave the hospital and meet up once again, where they move in together. Between his idiosyncrasies and her delusions, they find rooming together and, later, being in a relationship together, harder than they first hypothesized. But over time they work out the kinks, and then during an unconventional honeymoon, after an equally unconventional wedding, the two witness a UFO landing and ominous images warning them of an upcoming alien invasion. Now it's up to two people, with a combined total of eighteen mental hospital stays, to warn the world about the extraterrestrials coming to wipe out human existence.