Castle flew to the Final Frontier this week.
Next Monday, meanwhile, we go behind the music with our favorite author and detective.
Look for C. Thomas Howell to guest star on "Swan Song," which finds Kate and Rick looking into the murder to a rock band guitarist. With a documentary crew having been following around the victim, these folks will proceed to turn their cameras on the investigation.
Watch the ABC trailer below for a fun idea of what we can expect: