This guide is suitable for current RuneScape and Old School.
Talk to the monk outside Paterdomus (the Temple on the Salve). He will ask you to make an experimental weapon for him: a bowsword. Get a mithril 2h sword, and use it on Doric's whetstone, in order to get a slender blade. Then, use a bowstring on it to string the sword.
Return to the monk, and give him the sword.
Taking the Pouch to Entrana
He will in turn, ask you to give a gift to the monks on Entrana, because he cannot make it to an important ceremony. You must place the orb he gives you inside a Large Pouch - the sort used for Runecrafting. You are told to take it to Entrana via the abyss, as a surprise. If you do attempt to use the boat or balloon, you won't be allowed through with the pouch.
Go to the Zamorak Mage north of Edgeville, and travel to the abyss. Climb past one of the obstacles that require no items, such as the eyes, or the small gap. Once in the inner ring, travel through the law rift, and exit to Entrana. Go over to the altar, and place the pouch on it. A cutscene will ensue.
It emerges that the orb was actually a teleport beacon you'd been unknowingly given to plant, and allow an assassin onto the island, so he could steal the relic around which the ceremony was centred.
Talk to the High Priest, and he'll instruct you to return to the monk, to try and find out what's going on. Upon returning however, you find the monk, or at least, a monk, lying dead.
Reporting to Sir Tiffy
Return and tell the High Priest what you've found. Feeling uneasy, he'll ask you to report the goings on to Sir Tiffy Cashien, in Falador Park. Travel there, and you'll discover he already knew about what'd happened.
He will tell you that the knights are working on what's happening, and with the knowledge provided by you, should be able to draw up tactics.
Congratulations! Quest Complete!
Guide Made by: Deathslayer
Corrections submitted by: Tom, Jex, Dark, Power of Five