|First appearance||The Chrysanthemum and the Sword (mentioned)|
Don discovers a tape that Roger was using to record his memoirs. On that tape Roger mentions that Evans had preformed an unnecessary orchiectomy on Bertram Cooper. He then jokingly postulates that Cooper had him killed. ("The Suitcase")
"Why don't we just bring Dr. Lyle Evans in here?"
"Who is Dr. Lyle Evans??"
--Roger Sterling and Pete Campbell, "The Chrysanthemum and the Sword"