By James Hibberd
July 11, 2015 at 12:00 PM EDT

One major geek-tastic title that was seemingly absent from Comic-Con this year was HBO’s upcoming sci-fi drama Westworld. There was no panel, no massive poster covering a hotel, no branded pedicabs. 

But on Saturday, executive producer Jonathan Nolan decided to show a surprise trailer for Westworld during the panel for his other show—CBS’ Person of Interest

The trailer will not be posted online, but HBO did release some photos, below. The pics include first looks at stars James Marsden, Evan Rachel Wood, Thandie Newton, Anthony Hopkins, Jeffrey Wright and Ed Harris in the series version of Michael Crichton’s 1973 techno-thriller about androids run amok at a fantasy-fulfilling theme park.

For more on Westworld, check out our deep-dive interview with the producers