On 7 September her next escort duty was the Arctic convoy PQ 18 to the Soviet Union in which she was leader of the close escort. She arrived in Arkhangelsk on 21 September 1942 after a seven-day running battle, in which 13 ships were sunk, while 3 U-boats were destroyed and 40 aircraft claimed shot down. In October she was in Liverpool to have extra armour plating added to her bridge and bow in preparation for the invasion of North Africa.