Abduction: Chapter 2 [RELEASE] (Chapter 1 download included)

[bobbo]

Let me know if you need a more specific hint.

Thanks, got it!

Spoiler below!

I didn't even think about solving the letters because I thought they were used somewhere else as this riddle seemed to have something to do with numbers only. Also, I was too serious about the numbers in the note: I thought the "one" would be a number, too, also I thought there was a second "5", because the "five" siblings were mentioned twice.