The friendship between Laurel and Susannah is the real soul of this show. Seeing them try to navigate a "normal" summer while knowing it might be their last one like this is heartbreaking. Final Thoughts
(I can make it more "shipper" focused).
We see more of Susannah’s struggle with her cancer recurrence. The "Tan Lines" title is a metaphor—looking at what’s changed and what stays the same. [S1E5] Tan Lines