The road to Ben and Lyle's wedding is proving a bumpy one. Ben hasn't even told his family he's getting hitched to a shapeshifting merman, and he's not the only one worried. When Lyle's tearaway sister, Cully, whisks Lyle away on the merfolk equivalent of a stag do, she questions whether marriage is what Lyle needs anyhow. A merman should roam the seas and seek adventure, not work in an ice-cream parlour and worry about the rent.

With rumours flying among merfolk that Lyle is a dragon shifter, adventure seeks out Lyle, whether he wants it or not. Cully and Ben must set their differences aside to save Lyle from a gang wishing to steal his magical powers, which are in reality waning, possibly life-threateningly so. Lyle soon realizes it's going to take a miracle for him to make it to the wedding, forcing Ben to embrace magic and become something other an "ordinary" guy...