In the rush to escape , T - Dog accidentally drops the handcuff key for Merle down a sewage drain .
They are forced to abandon T - Dog ; however , T - Dog secures the roof access door with a heavy chain to give Merle some protection .
In the rush to escape , T - Dog accidentally drops the handcuff key for Merle down a sewage drain , and they are forced to abandon him ; however , T - Dog secures the roof access door with a heavy chain to give Merle some protection .