Hoxton was one of the four original members of the payday heist group until between the events of payday 1 and 2 he was ratted out arrested and since then has been waiting in jail, until now. The heist starts with you intercepting a convoy leading Hoxton to a retrial escorting him into an armored truck and guiding the truck down the streets of D.C. The second part has your crew help Hoxton break into the F.B.I. and search their servers for whoever had him arrested. Upon completion of the heist you're allowed to now finally play as the foul mouthed British man that is Hoxton (the Hoxton already in the group who is Dallas' brother has been renamed to Houston) you also unlock a toothbrush shank melee weapon.
The crimefest included a host of other new features including a revamped skill system, the previously mentioned new masks and weapons, the ability to change the time of day on some heists, and a few other things (The game is also currently on sale for 75% off and the original for 90% off I recommend grabbing both.)