Complex sentence: Similar to detectives such as Sherlock Holmes and Hercule Poirot, he is an London-based "private detective" in the 1930 era, who is specialized in curious, inexplicable case, strange conspiracy and others.
Split into simpler sentences: Similar to detectives such as Sherlock Holmes and Hercule Poirot, he is an "private detective" based in London in the 1930 era. He is specialized in curious, inexplicable case, strange conspiracy and others.