[X] Wrap the dagger tightly in cloth and rope, better to take it with us and secure than leave it here. Later can have it examined and properly destroyed if needed, or use if proven safe. It could even be important evidence of our mission should it have any relation to standing stones later.
[X] Write-In: Point out the strange dagger to Inge. It may be a piece of the puzzle of what's going on here and, given that she is more versed in these strange magics than you, she might know if it is even safe to touch. For all you know, it is some cursed blade.