This episodes' plot really was paper thin:
Burnham has to solve a mind puzzle where the solution is to cry. It takes place in a library, but neither the plot, not the themes, nor anything else had anything to do with books, knowledge of, well, libraries. At the end the Breen catch up.
However...
... I really liked that emotional scene!
And I have hated so, so, so many of Burnham's crying scenes before. Because they always felt fake, artificial, overdramatic - like soap opera or the Tennant-era Dr Who sapiness.
This scene though, Burnham just introspecting, felt very real, and very honest, and Sonequa's acting was just fantastic.
Also, on a side note, David Ajala is an absolute Goat and this shows secret charisma weapon.