I Swore On the River Styx I'd Come Back

Leo Valdez has lead a normal life since the war against Gaea: Attends Stanford on a scholarship for engineering, fights monsters every now and then, and goes to frat parties. But everything changes when he's kidnapped by Hades' minions for a quest for... Nico? A quest from a god is a once-in-a-lifetime thing, but even Leo can see that there's a deeper meaning somewhere...