in search of
Also, in quest of. Looking for, seeking, as in They went to California in search of gold, or I went to the library in quest of a quiet place to read. The first term dates from the mid-1400s, the second from the second half of the 1500s.
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.