Most of the time comparing the original and a translation is fairly straightforward. Occasionally one finds places where one wonders where the translation came from. The Septuagint for Isaiah 21:4 is one of those:
ἡ καρδία μου πλανᾶται καὶ ἡ ἀνομία με βαπτίζει ἡ ψυχή μου ἐφέστηκεν εἰς φόβον
My heart wanders and iniquity baptizes me. My soul stands in fear. (Isaiah 21:4 LXX)
Nothing in the Hebrew leads us to expect this. The resultant text is interesting but not what other translations say. One wonders where on earth this came from.