The countdown is on as Annie and AJ prepare for their first New Year's Eve party in Shieldinch, but old wounds threaten to ruin the festivities as they are forced to confront their marriage head-on. Caitlin pays the price for an extravagant Christmas when she finds herself short on rent money again, and Bob avoids telling Ellie he's moving in with Angus. A familiar face makes a dramatic return to Shieldinch.