Differential pulley load, and an endless rope looped around the pulleys. To avoid slippage, the rope is usually replaced by a chain, and the connected pulleys by sprockets. The two sections of chain carrying the single pulley exert opposing and unequal torques on the connected pulleys, such that only the "difference" of these torques has to be compensated manually by pulling the loose part of the chain. This leads to a mechanical advantage: the force needed to lift a load is only a fraction of the load's weight. At the same time, the distance the load is lifted is smaller than the
Hook (Once Upon a Time) memories. Upon recalling what Emma did to him, Hook immediately renews his plot to revive every Dark One and kill Rumplestiltskin. However, after a confrontation with Emma and Regina, Hook has a crisis of conscience and turns on the Dark Ones. Subsequently, Hook sacrifices his life to destroy the Darkness once and for all. However, upon the discovery that Gold has betrayed Hook to take back his power, Emma blackmails him into helping her get into the Underworld, so that she may launch a mission to revive him. In the Underworld, Hook is tortured by Hades. However, with the help