He's not at his place of business, which Kendra refers to as the Abacus --
How do I find the Abacus?
-- so he must be at home. You'll find information about where he lives in his office at the Abacus, or at least Joey will.
What should Joey do in the Abacus office?
Emil's desktop is a picture of Emil and Kendra in front of "the Exeter House." Have Rosa search for this on her phone, and it'll appear on your map.
What should I say to Emil?