We have all seen That Guy. He's the one who tosses off a quote from Monty Python and the Holy Grail, gets a laugh, and then continues tossing off quotes for the next five minutes while everyone gets progressively more uncomfortable. That Guy thinks that because the joke was funny, he should tell it again, and he won't stop until that joke is dead on the ground.
When I set out to write a sequel to The Palace Job, I wanted to keep things fresh and fun, but I was worried about losing what I loved about the world and the heroes. I was determined to avoid, at all costs, being That Guy.
My two favorite series in the funny crime fantasy genre, a somewhat stretchy and generously defined genre I just made up, are Terry Pratchett's City Watch series (a subset of his Discworld books) and Jim Butcher's Dresden Files. The books in both series vary in tone (and in both cases, often grow darker and more complex), but both still make me laugh out loud, and both have kept a core group of characters funny and lovable for many years by doing all the things I was initially afraid to do.
Circumstances Change, People Grow: In Guards! Guards!, Sam Vimes is a down-on-his-luck captain in the Night Watch, and Carrot is a wide-eyed new recruit. Many authors would have left them in that state forever, because a cranky cynical Vimes and a naive Carrot are hilarious. By the time we get to Thud!, though, Vimes is a respected commander with a wife and family, and Captain Carrot is older and wiser... and they're still just as funny, and more importantly, still themselves. Vimes directs his world-weary cynicism at nobles instead of cutpurses now, but his attitude remains the same. Carrot may know how the world works, but he's still fundamentally noble and decent in a world of people who aren't. Changing the circumstances lets the characters grow up instead of growing stale, and gives Pratchett constant new material for his heroes to bounce off of in their adventures.
If is Less Fun than How: In Storm Front, the first novel of the Dresden Files, private detective and wizard Harry Dresden is at one point handcuffed to a railing, being attacked by giant scorpions, in a building that is on fire, and that is not actually the most dangerous part of the scene in question. By the time we get to Skin Game, readers have seen Dresden deal with a demon in his head, become bound in service to the queen of the dark fairies, and debatably die. I was worried about how to keep readers entertained with threats, given that at the end of my first book, it was clear that all my heroes got out alive. What I realized from reading Butcher is that it doesn't matter that I know Harry Dresden is going to survive. What matters is how it happens. There are much more entertaining things to do to the heroes than just kill them, and the how can keep the reader invested.
My new novel, The Prophecy Con, moves my heroes forward without changing what I loved about them when I wrote them the first time. I look forward to seeing whether I have been That Guy.