Áine tells Frank that things are getting serious between her and Peter-Brian, so Frank and Doofus set out to expose him as the 'yoked-up party boy' Frank's sure he is. But in the process of collecting evidence against him, Frank starts to fall under his spell - and Doofus becomes worried Frank's fallen for the enemy. How will this new friendship affect Frank's relationship with Áine? Will Pee-Bee's Big Adventure threaten Doofus's previously uncontested position as Frank's bestie? Meanwhile, Mary takes on a tenant or two to cover the mortgage - and they couldn't be more different.