Over its 13 seasons, Chicago Fire episodes have run the gamut of emotional scale. “A Coffin That Small” is heartbreaking, as is “Sacred Grounds,” with the latter featuring the last moments of fan-favorite character Otis (Yuri Sardarov). The intensity of episodes like “My Lucky Day” and “The Path of Destruction” had viewers glued to their seats, anxious to find out what happened next. On the lighter end — Chicago Fire is easily the most lighthearted in the One Chicago franchise — episodes like “Out With a Bang,” where Cruz (Joe Miñoso) and Capp (Randy Flagler) pour cement mix down the toilets at Molly’s only to learn that the bank isn’t shutting it down, feature legitimately funny moments. There’s literally something for everyone in the series, with fans quick to name some of their favorite episodes. But episodes that stay with you, ones you can’t stop thinking about, aren’t always quite the same. Sometimes, the episodes that live rent-free in your head may not even be particularly good, yet something happens within them that strikes a chord. For me, that episode is Season 13’s “In the Trenches, Part I.”