I just watched this episode for the second time and was remembering how great it is. The case is terrific, although tragic in the end and the unique methods the team has to resort to solving it make this installment memorable.
I think what I love so much about this show are the moments: Sweets' (badly expressed) concern for his friends, Jack and Angela coming to terms with the possibility of their child's blindness and realizing that together there is nothing that they can't handle. That's what a good marriage is: two people together doing more than either one can do alone. We don't see too much of that on TV or in the news.
Then there's the humor! Hodgins' terrible but very funny potato jokes and especially the stunt where he loses his balance and come crashing down, covering Wendell with dye in the process. I loved it!!
The final scene with the meaningful conversation about the difference between strength and imperviousness and the burning of the dates of when they think they're going to get together was sweet. I loved Booth's line about how burning a letter represents releasing it to the Universe. I've done that from time to time and It's a neat thing to do,