The 12th and final season of Fox's crime procedural drama series "Bones" is coming to an end. But the thrill is not about to die down just yet. A promo for the penultimate episode of the season shows that a bomb will threaten the lives of the Jeffersonians, the main characters included.

As revealed in the trailer for "Bones" episode 11, titled "The Day in the Life," Dr. Temperance Brennan (Emily Deschanel) and Agent Seeley Booth (David Boreanaz) will be trapped in the Jeffersonian Institution, along with a number of their colleagues, when the bomb goes off. Brennan and Booth suspect that a man wants Brennan and her family dead. The bomb could easily be his way of getting rid of the anthropologist.

In the promo, Booth will discover the bomb in the Institution way too late. Moments before the bomb is set to detonate, it seems like the agent will manage to inform and evacuate a number of workers. While some will make it out of the door safely, the emergency lockdown procedure of the building will keep the pair inside.

The synopsis reveals that the storylines of the well-loved characters of the series will be coming to a close. But could the bomb put an end to Brennan and Booth's storylines? As of now, that remains unclear.

Elsewhere in the episode, viewers will see Brennan testifying in Zach's (Eric Millegan) trial, Angela Montenegro (Michaela Conlin) announcing a big news, and Agent James Aubrey (John Boyd) and Jessica Warren (Laura Spencer) settling about their plans for their future.

In the penultimate episode, Mark Kovac (Gerard Celasco) will break out of prison, and will once again pose a threat to anyone who would come across his path. Perhaps Kovac will be behind the attack on the Jeffersonians.

"Bones" season 12 episode 11, titled "The Day in the Life," airs on Tuesday, March 21, at 9 p.m. EDT on Fox.