Captain Marvel #21 is an action-packed story from writer Kelly Thompson, penciler Cory Smith, inker Adriano Di Benedetto, colorist Tamra Bonvillain, and letterer VC's Clayton Cowles. Wrapping up the Empyre tie-in arc while also revealing the fate of Carol's newfound sister Lauri-ell. 

Last issue, the war with the Cotati, came to Carol's backyard when her neighbor and friend Kit Renner (aka Lieutenant Trouble) was kidnapped by the aliens. Luckily for Kit, Lauri-ell is around to summon Captain Marvel, War Machine, Hazmat, and Spider-Woman. With so many heavy-hitters in one spot, the Cotati don't stand a chance. 

Captain Marvel #21 is a middle-of-the-road story from Thompson. There's a lot of action at the cost of limited plot and character development. There's a few moments where Carol and Lauri-ell get to bond as sisters, something that helps flesh out both characters, but most of the story is just fighting the Cotati. And because Captain Marvel #21 takes place before Empyre #4, Thompson has to try and wrap up the story without actually being able to tell readers exactly how Captain Marvel's involvement in the conflict ends. Fortunately, Thompson does a decent job with tying up most of the loose ends, so readers don't need to also read Empyre #4 if they don't want to.  

During this Empyre tie-in arc, the art has been very strong, and Captain Marvel #21 is no different; Smith and Di Benedetto have been an asset to the creative team during this arc. Bonvillian's use of muted neutral colors contrasts with the Accusers and their hammers' alien green light, causing them to stand out and look otherworldly. And Lauri-ell shines in the fight scenes during this issue, which gives Cowles the chance to let loose with plenty of action words. 

The end of the Empyre event feels like a relief because the tie-in issues haven't been as interesting as other arcs have been. What kept this arc from completely falling flat was the introduction of Lauri-ell as a character, as well as the inclusion of Captain Marvel's close friends War Machine, Hazmat, and Spider-Woman as Accusers. While it would be great to see those characters come back in future issues, hopefully, they won't have the pressure of carrying the entire arc on their shoulders. 

GRADE: C