DEXTER” is coming to a bloody end, and The ENQUIRER has learned the deadly details that will leave fans of the Showtime hit shocked over the killer finale!

We’re about to reveal the show’s biggest secrets, so stop reading NOW if you don’t want to know the drama that’s about to unfold for serial killer Dexter Morgan, played by Michael C. Hall, in the series’ eighth and final season.

Dexter has been getting away with murder for years, but one of his last kills is not only going to blow people away, it’s going to make a whole lot of loyal fans very angry,” said an insider.

The ENQUIRER has learned that in the final episode, Dexter kills his sister, Debra, who’s played by the actor’s real-life ex-wife, 33-year-old Jennifer Carpenter.

“Debra knows too much (about his killings) and she’s become more unraveled than ever,” noted the insider.

Golden Globe award winner Hall, 42, stars as the Miami Metro Police Department’s forensic blood pattern analyst who channels his urge to kill by following “The Code” he learned from his father. The lovable sociopath only kills people after finding conclusive evidence that they’re guilty of murder.

According to the source, the writers and producers anguished over the finale, but it’s an ending they’ve talked about for years. The explosive episode – titled “Remember the Monsters?” – airs on Sept. 22.

“The ‘Dexter’ finale is going to be debated for a long time to come,” added the insider. “Fans don’t want Debra dead because they’re emotionally attached to all the characters.”

"It’s going to blow people away”