Hunter x Hunter (2011) - episode 57 - 01 Dec, 2012

Gon and Killua are captives of the spiders. Kurapika, Melody, and Leorio hatch a plan to capture Chrollo and use him as leverage to force the remaining Phantom Troupe members to release Gon and Killua. (Source: Wikipedia) Yorknew City arc/Phantom Troupe arc: (21/22)