Taking place at London’s Newgate Prison, a prison that is infamous for its executions, which took place in front of the prison, in view of a massive crowd(1). Sweeney Todd is shown wielding a hammer that he is attempting to commit suicide with. Three additional prisoners (or guards?) are shown as well. Two are clearly attempting to stop Todd from killing himself. One of them is holding a lantern in a one hand, lighting the dark cell and providing all of the light present in the image. He is reaching up with his other hand towards Todd’s wrist to stop him from swinging the hammer. The other is grabbing Todd’s hair in an attempt to subdue him. The third prisoner is kneeling in front of Todd with a shank in his left hand. It is not clear what he is doing.
(1)http://www.ph.ucla.edu/epi/snow/1859map/newgate_prison_a2.html