Captain Marvel: Earth's Mightiest Hero Vol. 4 by Kelly Sue DeConnick (Writer), Warren Ellis (Writer), Kelly Thompson (Writer), David Lopez (Artist), Marcio Takara (Artist), Laura Braga (Artist), Lee Loughridge (Colorist), and VC's Joe Caramagna (Letterer)

In the previous book, Captain Marvel decided to sign up for a year in space as the Avengers representative there to keep a lookout for things.  Her first assignment is to return a pod with a Nowalian, who turns out to be Tic to her home planet of Torfa where they are being oppressed by J'son and the Haffensye, pirates who are working for J'son, the ruler of Spartax and Star Lord's dad.  She helps the people of Torfa win their freedom and Tic leaves with her.  Rocket tries to set up a buyer for Carol's cat, which is actually a flerken, a rare space creature that can be used as a weapon, but word gets out and someone shows up to steal it.  Carol meets a rock star who has the ability to travel anywhere in the blink of an eye and when she helps her the rock star transports her back to earth for twenty-four hours where Carol sees Tracy who is very sick, unconscious, and might not make it to her return. 

When she returns back to the ship, Tic and the cat flerken are gone and the ship is damaged.  She brings the ship, Harrison, back online and finds out that Haffensye came and attacked the ship to get the flerken.  Captain Marvel decides to take a shortcut through the endless envelope which proves to be a spacial anomaly that will take ten times as long to get there then if she'd just followed their path.  But she finds some unusual things inside the envelope on her way to try to rescue Tic and the cat.

Included is a storyline where Earth-616 and Earth 1610 were unable to save the multiverse and all that remains is Battleworld, a planet composed of fragments of worlds that no longer exist maintained by its god and master, Victor Von Doom.  Captain Marvel is in charge of the Carol Corps, an elite flying force of women.  There's also the Thor Corps the police force where each is selected by Doom himself from all the different worlds.  Kit is a member of the Thor Corps. But not all accept that there is nothing beyond the void or that the enemy that they are fighting is really Ultron.  The Carol Corps intend to retrofit their planes to fly into the void, but first, they must get past the Thor Corps and the Baroness, Colonel Carol Danvers superior.  

Also included in this comic is a story from the Black Vortex where Captain Marvel is tasked with delivering the magic mirror to Kitty Pryde and avoid a great many people who want it themselves first.  There is a short storyline where Carol says goodbye to Tracy and Tracy leaves behind a message for her that will tug at your heartstrings and make you laugh just like Tracy could sometimes do as a person.  This was a great book and a fine ending to a stellar series.

Link to Amazon:  https://www.amazon.com/Captain-Marvel-Earths-Mightiest-Hero/dp/1302902695/ref=sr_1_1?ie=UTF8&qid=1521808760&sr=8-1&keywords=captain+marvel+volume+4&dpID=51ctZPPK1-L&preST=_SY291_BO1,204,203,200_QL40_&dpSrc=srch