in search of (something)
Hunting, seeking, or searching for something. I'm going to town in search of a new book to read. The border is always filled with refugees in search of a better future.
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.