Severide has been grieving the death of his best friend Shay all season on Chicago Fire, but on Tuesday, he'll be tested like he has never before.

In this exclusive sneak peek from Tuesday's major crossover episode with Chicago P.D. (10/9c, NBC), Severide (Taylor Kinney) gets the lowdown on the man suspected to have been behind the arson that killed Shay (Lauren German).

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However, both Severide and his colleague are shocked when the suspect (Robert Knepper) approaches him about Shay's death.

Does he confess? What is Severide's next move? Check out the video below to find out:

Next week's crossover begins on Chicago Fire on Tuesday at 10/9c on NBC and continues on Chicago P.D. on Wednesday at 10/9c.