Mystery Writers of America Grand Master Lawrence Block turns 85 June 24. And what better way to celebrate than to publish a Borgesian memoir of his most celebrated character? The Autobiography of Matthew Scudder, the 20th entry in a series that Block kicked off in 1976, will appeal primarily to fans of the New York City PI, who will find it at turns fascinating, satisfying and surprisingly moving.

Block always has a narrative trick or two up his sleeve, so I read the first section of the book—purportedly the memoir of Scudder’s early years written by the not-so-fictional character himself, with encouragement from the author who turned the detective’s crime-solving exploits into best-selling novels—waiting for a clever shift into one last gritty mystery.

Instead, Block—or Scudder, if we stick with the conceit, and why shouldn’t we have some fun with it, too?—delivers a straightforward autobiography that gives fans of the novels fresh insights into Matt’s early years. We learn for the first time of a little brother who died shortly after he was born, as well as the family dynamic that led young Matty to join the NYPD and lose himself in the bottle for many years.

The later sections, which add new details and depth to Scudder’s relationship with his longtime companion Elaine and the deadly rampage of psychopath James Leo Motley that almost took both their lives, will send many readers scrambling for a return ticket to the boneyard. In considering his interactions with Motley, Scudder strikes the book’s most complex emotional chords:

“I’ve apparently reserved my deepest regret for a sin of omission, an instance where I might have killed but didn’t. I think of the lives that might have been spared, the harm that might have been averted. Why, for the love of God, didn’t I kill James Leo Motley the first time I had the chance?”

Scudder’s exploration of that question’s broader implications will prove quite moving for readers who have followed his exploits in real time for nearly half a century.

Fare thee well, Matt Scudder. You picked a hell of a novelist to chronicle your most sensational cases, and you’ve done him proud in telling the story of the rest of your life. And happy birthday, LB. Thanks for sharing your present with us.

The Autobiography of Matthew Scudder publishes June 24 and is available for preorder now. You can read a free preview here.