First of all, I feel disappointed to myself. I had large thoughts and expectations for this show and I just realized that Free! is just a typical 13-episode summer show.
Episode 1 - I feel very excited and amazed that it made me squeal as an ordinary fangirl. I kept on yelling: "KYAAAA" and "KYAAAA" everywhere.
Episode 2-4 - And I feel normal. Less "KYAAAA" and such stupid acts. The story's well built though... And you can feel the change of pace and character development.
Episode 5 - I was shocked. it left me cliffhanged like other viewers. The "save me, i'm drowning!" scene left my jaws open. It was a nice cut. It made me expect a BUNCH of things but...
Episode 6 - I feel that Rei and Makoto are fine... They're swimmers! Of course! This episode may just talk about the fear of Makoto in the ocean
Contains MASSIVE spoilers. View at your own risk, guys!
Episode 7 -
Episode 8 -
Episode 9 -
Episode 10-13 - VERDICT: One word. Friendship. They'll be friends again and swim together. The end.
If you're wondering WHY I do have some ideas. It's a) Guess and b) Knew it all along! But I DO NOT intend spoiling you (that's why I added a spoiler button) and I do not know the ending myself.