Crimson Crystal Clue

As the colossus falls under the weight of your attacks, you notice for the first time that it was holding a red crystal fragment.

While it was small and unnoticeable in the mountain giant's hand, it's a fairly hefty piece for you to carry around. It also suspiciously looks like it's a piece of the giant crystal in the middle of the ridge.

It's most definitely a clue as to the strangeness that is occurring here, and you're sure that the druids at the Cenarion Post to the south will want to see it.