The second season of the Marvel/Netflix series 'The Punisher' has begun filming. Photos have surfaced in New York City from where series star Jon Bernthal has returned to work as Frank Castle. Marvel and Netflix have not released any official plot details about season 2, but character descriptions which have surfaced online suggest the show will take on the 2005 story arc “The Slavers.” The storyline is considered by critics to be one of the best and arguably the darkest Punisher tales ever.