A co-creator, co-writer and star of hit series like “Sherlock” and “The League of Gentlemen” Britain’s Mark Gatiss brings his customary brio to his new PBS murder mystery-detective series “Bookish” which premieres tonight at 10.

Gatiss, 59, created, writes and stars as antiquarian bookshop owner Gabriel Book who with his encyclopedic knowledge of literature, history and the thousands of books lining his shelves helps police solve mysterious crimes in 1946 London.

“All my life, I’ve wanted to be a detective. And I’ve always wanted to really lead my own show.

“I’ve had this idea in my head,” Gatiss added in a virtual interview from London, “for nearly 10 years actually.

“Book is a synthesis of things I’ve always loved and I think the postwar period is extremely — and oddly! — under-examined.

“It’s a very interesting, strange time when the world is smashed to bits. But also full of optimism. And I knew I wanted him to be a gay man in a dangerous world.”

Gay Gabriel Book may be, but he’s married to his childhood best friend Trottie (Polly Walker, “Bridgerton,” “Line of Duty”), whose wallpaper shop is next door.

“It’s called a ‘lavender marriage.’ I’ve taken no credit for this, but there seems to be an upsurge in reports of them in Hollywood recently.

“Postwar, there were very famous ones, usually between a gay man and a gay woman. But also between one gay partner and a straight partner, which is what this is.

“So Book and Trottie were childhood friends who are in this mutually convenient relationship which is outwardly respectable but inwardly more complicated.”

A key element in the first mystery is the rationing.  No one in 1946 could imagine British rationing would continue another 10 years.

“It gets worse — that’s the terrible thing,” Gatiss said. “One of the most difficult things for people to cope with was they’d won the war — and didn’t seem to get any benefit from it because rationing was a really big thing.

“In fact, I’m trying to ensure that in Series 2 we see more of people taking their leftovers home. Because they absolutely would! I mean, there was no waste at all.

“I grew up never leaving anything on my plate. First of all, because it wasn’t allowed. Secondly, because it wouldn’t stay there. My dad would eat anything.

“It’s interesting to use a murder mystery to talk about social commentary and throw a light on our own time through the past.

“Particularly in terms of was then a dangerous world for a gay person, and we are living in increasingly dangerous times again.”

“Bookish” airs on GBH Sundays at 10 p.m.