Nero is keen to get home to see his dad who is visiting. But when he gets stuck in 4 O'Clock Club he snitches on Eli and Owen in order to be let out early. Eli and Owen try to start an online viral to rival 'planking'. They come up with the idea of 'mug-treeing' - balancing as many mugs on yourself as you can. Lacking supplies, they decide to sneak into the staff room after school and use the piles of mugs there. Up for an adventure, most of the 4 O'Clock gang join them. Unfortunately, due to a defective security system they get trapped in the school and Nero has to save the day by rescuing them. Meanwhile, Josh bunks off school to go to an all-day music conference, but when he gets there he finds Miss Parkwood bunking off too. The pair of them end up singing a cheesy duet.