After fueling at Midway on 8 October, "Thresher" sailed for the Hawaiian Islands and arrived at Pearl Harbor on 12 October 1944. Following a lengthy refit, "Thresher" got underway on 31 January 1945 for the Marianas, in company with , , and . Remaining at Saipan overnight on 12–13 February, the impromptu wolf pack pushed on toward its assigned patrol areas north of Luzon. However, only two of "Thresher"s contacts developed into attacks. One failed due to the target's shallow draft; and the second contact evaded. "Thresher" did, however, conduct air-sea guard patrols; and conducted a shore bombardment of Basco Harbor, Batan Island, on 28 March. The latter part of this patrol was conducted in company with "Piranha" and .