Hell Bent by Leigh Bardugo:

Wealth. Power. Murder. Magic. Alex Stern is back and the Ivy League is going straight to hell in #1 New York Times bestselling author Leigh Bardugo’s Hell Bent.

Find a gateway to the underworld. Steal a soul out of hell. A simple plan, except people who make this particular journey rarely come back. But Galaxy “Alex” Stern is determined to break Darlington out of purgatory―even if it costs her a future at Lethe and at Yale