Complete the word search!
Also, given the image of Caesar in the corner, I thought that maybe it indicated it was Caesar's Cipher?
Do the same thing as in lettersoup and take the non-shaded characters.
Translating just the first line with an automatic ROT decrypter will tell you that ROT7 works and tells you to only look at the last line.
Go to the last line and decrypt to get the flag.

flag{astheyflyacross}