Eric's art gallery is losing money, and even though his psychiatrist wife wants to help, she can't do much to cheer him up. When a young, sexy woman named Toni accepts a sales position at the gallery, she instantly brings it back to life, jump-starting Eric's troubled marriage in the process. But the marital problems soon come back, prompting accusations that Eric is having an affair with Toni.

Doctor Baines has been conducting genetic experiments on piranhas and has made them virtually unstoppable. Unfortunately, his assistants, Maggie and Paul, accidentally release the hybrids into the Lost River Lake threatening to destroy everyone in their path. Can they prevent the flesh-eating piranhas from escaping into the ocean and spawning?

Will and Maura, despite their marital problems, decide to come to Ireland and live on Maura's ancestral estate, bringing with them their daughter Aubrey. But soon weird happenings around the house lead a local priest to confess that Maura's ancestors practiced black magic, and Maura's own insecurities threaten to bring her into the evil fold.