Someone from Marshall's past is back and this time she's not going to give him up so easily.

Now that Fionna's officially given up on Prince Gumball, she'll have to notice the totally radical Vampire King, right? How could she not? He's been there for her forever so now all he has to do is-wait, she's dating Flame Prince? Well, that simply won't do.

Fionna and Cake are moving into the tree house. The only problem is the bored vampire king who quickly develops an interest in harassing them. Will they prevail? Or will the tree house continue to smell like tomato sauce forever? FionnaxMarshall Lee

A story of a new Vampire Queen. A story of how it all ended for him. A story of how they could of spent a life time together. A story about a human girl, her cat and the Vampire King. Is back on!

Marshal Lee and Fionna both struggle admitting to themselves and each other their growing feelings towards one another: As Gumball continuously breaks Fionna's heart, she realizes her best friend has always been the one to mend it.

One day Fiona and Cake find a strange boy in their home who claims it's his, they go to Prince Gumball looking for help. They slowly realize that the strange boy, a vampire named Marshal Lee The Vampire King, and Prince Gumball have a complicated past.