Bones Fox
Brennan (Emily Deschanel, pictured here) interrogates Jeannine Kovac (Brittany Shaw Johns, pictured here) in “Bones” series finale. Patrick McElhenney/Fox

It’s hard to imagine a life without “Bones.” The Fox series became a staple primetime drama for many fans during its long run that lasted 12 seasons. The penultimate episode featured several guest-stars and resolved an important storyline regarding former squintern Zack Addy (Eric Millegan). However, one mystery continues to baffle fans.

The 447 mystery has been one of the longest unsolved one in “Bones.” The number has appeared a number of times during the course of the series. In a Season 4 episode, Booth’s (David Boreanaz) alarm clock reads 4:47, in another Season 5 episode, a murder victim’s apartment had an alarm clock that flashed 4:47, in a Season 7 episode, a newspaper headline read, “Hero of Highway 447,” and in two Season 11 episodes, the mysterious number was a code to Booth’s briefcase which was stacked with guns and a character’s apartment number.

READ: Who might die in “Bones’” final episode?

What does the number signify? More importantly, will fans get an answer about the importance of this vague number? TVLine reports that the mystery will remain unsolved but 447 figures into an extremely key moment in the final episode.

One fan theory on Reddit suggests that when 447 is turned upside down and flipped to the side it makes the letters LHH which could stand for Love Hart Hanson, who is the creator of “Bones.”

TVLine also reported that the series finale is a moving, funny, bittersweet and satisfying.

In other news, Boreanaz has been cast as the lead in a CBS Navy SEAL drama pilot, reports Deadline. In his first post-“Bones” role, the former “Angel” actor will portray a respected and committed leader of his assault team. His character, Jason, has been through a dozen deployments and these missions have left scars on him, both inside and outside.

“Bones” series finale airs Tuesday, March 28 at 9 p.m. EDT on Fox.