Complex sentence: The broadcast (announced by Billy Gilbert) is of a murder-mystery called'The 13th Murder'-it's at the point in the broadcast where Dr. Nemo (Billy Gilbert) is trying to murder Mary Dangerfield (Estelle Etterre).
Split into simpler sentences: The broadcast (announced by Billy Gilbert) is of a murder-mystery called'The 13th Murder'. It's at the point in the broadcast where Dr. Nemo (Billy Gilbert) is trying to murder Mary Dangerfield (Estelle Etterre).