A pretty fun, light read after John C. Wright.
Kangaroo (secret agent code name) has a superpower: he can open a portal to another universe, which is completely empty. Makes it perfect for storing or smuggling stuff! He is also employed by a sort-of future CIA. A few hundred years or so into the future, colonized Mars has recently become independent following a brutal war with Earth. Now, Kangaroo is on a (Disney-esque) cruise ship bound for Mars, ostensibly on vacation, albeit one forced on him by his boss.
It turns out that there is something sinister afoot. A few murders, a hijacking, and a threat to re-ignite the Mars-Earth war keep the story moving at a pretty good clip. Lots of humorous dialog.
My gripes (which are pretty modest) are 1) the stolen items out of cargo didn’t really need to be in the story and 2) the love interest fell for Kangaroo rather quickly – I kept thinking that she would turn out to be some bad guy trying the seduction angle on our hero, but nope. She just falls in love at the drop of a hat, I guess.