 Complete the following phrase:  After escorting the carrier to Freetown, Sierra Leone, and Takoradi, Ghana, in January 1941, Encounter rejoined Force H in time to participate in Operation Picket at the end of the month. This was an unsuccessful night torpedo attack by eight of Ark Royals Fairey Swordfish on the Tirso Dam in Sardinia. The British ships returned to Gibraltar on 4 February and began preparing for 