CSI “The Descent of Man” Season 9 Episode 19 April 7, 2009 CSI CSI Season 9 Episode 19, “The Descent of Man”: Watch a sneak peek of this new episode airing this Thursday April 9 at 9pm on CBS. Taylor Swift Guest stars. Read all our CSI coverage. Episode Synopsis: CSI “The Descent of Man” Season 9 Episode 19 – Nick’s case of a deceased skydiver takes an interesting turn when Catherine discovers there may be a connection between the skydiver and a mysterious double murder case, on CSI: CRIME SCENE INVESTIGATION, Thursday, April 9 (9:00-10:01 PM, ET/PT) on the CBS Television Network. Charisma Carpenter (“Buffy the Vampire Slayer”) and Greg Germann (“Ally McBeal”) guest star. Share this:Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on Reddit (Opens in new window)Click to share on Google+ (Opens in new window)Click to share on Tumblr (Opens in new window)Click to share on Pocket (Opens in new window)