TrekSpace has learned the titles of two upcoming episodes. The fifth episode of STAR TREK:DISCOVERY is titled “Choose Your Pain” and will be released on October 15th.
S01E05 CHOOSE YOUR PAIN
The sixth episode titled “Lethe” will be released on October 22nd. In Classical Greek, the word lethe literally means “oblivion”, “forgetfulness”, or “concealment”. Lethe was also the name of the Greek spirit of forgetfulness and oblivion, with whom the river was often identified [Wikipedia].
Also, Lethe was a female Human civilian at the rehab colony on Tantalus V in the 23rd century (Dagger of the Mind).