Cashing in Old Favors

M1 - Cashing in Old Favors is a mission in Deus Ex: Human Revolution.

Meet Sarif in the Penthouse
This is a brief story-only mission between leaving Detroit for the second time and arriving back in Hengsha. It takes place entirely in Sarif HQ. There are a few additional messages to be found on terminals, and some previously hacked terminals have been locked again. Most of the area is as you left it previously though.

Take the elevator up to Sarif's office to find Hugh Darrow waiting for you. After a brief exchange Sarif returns and talks to you briefly before sending you on your way.

Meet Malik at the helipad
Back downstairs, head out towards the helipad, stopping along the way to talk to Athene Margoulis in the cafeteria. Then just go to the helipad, talk to Malik, and it's off to Hengsha again.