John and Rodney captured by wraith

I am looking for a fairly old story, I think, where John and Rodney are captured by bad guys and fed to the wraith similar to the common ground story. I don't remember many of the details but I think they fed Rodney to the wraith first and John was trying to help him cope and then volunteering himself? Sorry the details are so vague but I have been going crazy trying to find it.