'Didn't It Rain' sees Hugh Laurie depart the sounds of New Orleans as he follows the trajectory of the blues upstream and into the American heartland. It includes songs dating back to early pioneers W.C. Handy ('St Louis. Blues') and Jelly Roll Morton ('I Hate A Man Like You') to more recent artists such as Dr. John ('Wild Honey') and Alan Price of The Animals ('Changes').

Jonathan Pine is working as the night manager of a Cairo hotel. He gets involved with a local woman who is the girlfriend of a local gangster. Through her relationship with the gangster she has acquired information linking illegal international arms sales with an English billionaire.

Susan Murphy gets turned into a giant monster on her wedding day when a meteorite from outer space hits her. She is taken to a secret government compound where she meets a ragtag group of monsters also rounded up over the years. As a last resort, under the guidance of General W.R. Monger, on a desperate order from The President, the motley group of Monsters are called into action to combat the aliens and save the world from imminent destruction.