Author Andrew Shaffer released a funny mystery novel last year.

“Hope Never Dies” followed narrator Joe Biden as he dealt with a murder mystery and his otherwise humdrum life after serving as vice president. Shaffer’s Biden was miffed with Barack Obama because the former president never spent any time with him.

Until … they worked together on solving the case that Biden partially stumbled onto, partially took on.

The cover of “Hope Never Dies” included a seal reading: “An Obama Biden Mystery.” The seal seemed a promise of more mysteries to come.

“Hope Rides Again” keeps the promise of that seal.

Here, Biden remains the narrator. He’s been on the road as part of a grueling book tour and is weighing a presidential run. He stops in Chicago to participate in a post-presidential Obama event.

Obama’s Blackberry is missing and Biden thinks he knows who has it — a kid he met a short time earlier. Biden tracks down the kid and discovers the teen has been shot.

Soon, Biden and Obama are on the case, looking for the shooter, a large load a guns coming into Chicago and the president’s phone.

Biden is sort of a Watson character here as well as the Sherlock character who claims the game’s afoot. Obama is more aloof; he becomes involved in the mystery but reluctantly so.

The books are reminiscent of Kinky Friedman’s mysteries from 20-some years ago. The “Hope” books are comic with touches of the philosophical. Unraveling the mystery is second to taking the journey.

Readers may enjoy imagining that the relationship Obama and Biden share in the book may be close to the friendship they have in real life.

By the end of “Hope Rides Again,” Biden is leaning toward running for president — which he is doing here in the real world.

Will there be a third Obama Biden Mystery?

It could depend on whether Biden is simply a candidate, a nominee or president.