Mariusz Czubaj is a cultural anthropologist and a bestselling author in Poland. His first crime novel featuring profiler Rudolf Heinz, 21:37 (21:37, 2008), won the High Calibre Award for the Best Polish Crime Novel in 2009. He has co-authored two crime novels with Marek Krajewski: Aleja samobójców (‘The Avenue of Suicides’, 2008) and Róże cmentarne (‘Graveyard Roses’, 2009). In 2011 he published the second book on Rudolf Heinz, Kołysanka dla mordercy (‘Lullaby for a Murderer’), and the third, Zanim znowu zabiję (‘Before I Kill Again’), was released in 2012.
21:37 is Czubaj’s first novel translated into English.