The town of Elmo experiences a record heatwave and Marin realizes the energy bars she's been feeding the raccoon living in her closet are making him sick. She turns to Jack for help and finds herself attracted to him, but doesn't know if she--or even Jack--is ready for a relationship. Across town passions stir between Patrick and Annie, and much to Theresa's surprise, between Ben and Sara, as things heat up.

The town of Elmo throws Marin a huge birthday celebration, but the unexpected arrival of her fun-loving younger sister, Liza, conjures up some unexpected insecurities for Marin. Now that Ben has asked Theresa to move out, tensions rise between Theresa and Sara, whom Ben is now dating. Meanwhile, Buzz finds Patrick's father's plane that had disappeared 26 years ago -- opening up Patrick's hope that the father he has never known could have survived and be alive somewhere.