Season three of serial-killer drama Dexter saw it emerge as one of the finest currently-running shows on American TV. Starring, of course, Michael C Hall in the title role, the show's exquisite writing generated an abundance of quality episodes for its third run, and off the back of its success, Showtime promptly commissioned both season four and season five.

It's season four that's currently heavily in production, though, and it starts again in around two months' time. But in advance of that, Showtime has released a promo trailer for the show's upcoming fourth season, complete with the tantalising exploration of Dexter the parent (as we saw with the previously released promotional poster). Let's not forget too what should be the masterful addition to the cast of Mr John Lithgow. We suspect we'll be talking about him a lot in the months to come...

If you want to take a look at the trailer, then click below. And then get ready for 27th September, when Dexter returns to US TV screens...