One of the Houses at The Institute. Their standard is unknown. House Mercury is home to the quick, the clever and the tricksters. Not much else is known about this house.

Proctor Mercury is a jovial and jittery man who often fiddles with his hands. He is small, squat and baby faced. He has coiled golden hair. He makes a strong argument to the Draft committee to select Darrow in the first round. However, they pass him over, intending to pick him in Round Two.

When Darrow and his army gain access to Olympus, he encounters Proctor Mercury, who is suprisingly agile with a razor.