Devious Minds

Forging the sword
You start this quest by speaking to the monk at Paterdomus. He requires a bow-sword. To make this bow-sword, take a mithril 2h sword to Doric's house and use it on the whetstone (level 65 Smithing required) to make a slender blade. Then use it with a bowstring to make the bow-sword.

Note: it is possible to use temporary boosts (dwarven stout, mature dwarven stout or spicy stew) to reach the required Smithing level.

Making the delivery
Give the bow-sword to the Monk and he will ask you to make a "delivery" to Entrana: he will give you an orb, and ask you to take it to the church in Entrana. The only way to do this is to hide the orb in a large pouch, then use the Abyss to reach the law altar, and finally exit the law altar using the portal to reach Entrana. Note: remember that you can't bring weapons or armour to Entrana, even through the Abyss.

Note: instead of using the abyss you are able to use a law altar teleport tablet obtainable by playing the Great Orb Project in the Runecrafting Guild. A law altar teleport tab requires 43 Runecrafting Guild tokens to purchase.

Walk to the church to the South, and use your large pouch on the altar. You will see a cutscene where some monks are walking toward the altar, one holding a mysterious Relic, and then a Ninja wielding the bow-sword teleports in the church, kills the monks and steals the relic! Also, you'll lose your Large Pouch as the teleport beacon inside it is destroyed. You'll have to get another one as it's not replaced during the quest.

Giving the news
While you're at the altar, recharge your prayer since it was drained when you entered the Abyss. Talk to the High Priest. He will tell you to return to the original monk at Paterdomus to investigate. Go back to Paterdomus to find a dead monk. Search him, then go to Entrana to talk to the High Priest again. He will ask you to inform Sir Tiffy Cashien at Falador Park. Quest Complete!

Reward

 * 1 Quest point
 * 5,000 experience
 * 5,000 experience
 * 6,500 experience

Trivia

 * Devious Minds has a similar name to the first ever version of RuneScape, Devious MUD
 * At the end, when the player reports to Sir Tiffy Cashien, he says "we'll be in touch," hinting at an as-of-yet unannounced sequel.
 * If you have completed One Small Favour then once the monk mentions "...one quick favour..." you reply: "Hey that sounds a little familiar..."
 * Originally, players could only enter the law altar after completion of the Troll Stronghold quest. As such, it was originally a requirement for Devious minds. Later, Troll Stronghold's reward was changed so that it was no longer a requirement for access to the Law Altar. Troll Stronghold was accordingly removed as a requirement for this quest.