Episode 4 of “The Talons of Weng Chiang” gives us the downfall of Li H'sen Chang. Dismissed by his master, ‘Weng Chiang’, Chang tries to get back in his good books by killing the Doctor–as a part of his stage act! It all goes horribly wrong, however. Brought to bay by the Doctor, Chang flees into the sewers, only to be attacked by the (fake looking) giant rats dwelling there.
Meanwhile, Weng Chiang and his other minions have broken into Professor Litefoot’s home and stolen an old Chinese cabinet–which just happens to be Time Cabinet he is looking for!