Horror From The Deep


  • 35 Agility
  • 40 Prayer (optional, but strongly recommended)
  • Ability to defeat level 100 Dagannoths (can be safespotted, but you will have to take a few ranged hits - Dagannoth Mother can hit for 24 in ranged)
  • Completion of Alfred Grimhand's Barcrawl miniquest


  • 1 Fire rune
  • 1 Water rune
  • 1 Air rune
  • 1 Earth rune
  • 1 Sword of any type (will be lost)
  • 1 Arrow of any type (will be lost)
  • 1 Molten glass
  • 1 Tinderbox
  • 1 Hammer
  • 60 Steel Nails
  • 2 Planks (obtainable during quest)
  • 1 Swamp Tar
  • Combat gear (Magic recommended)
  • Food (recommended)
  • Lyre/House teleports to Rellekka (recommended)


Speak to Larissa outside the Lighthouse to the north of the Barbarian Outpost to start the quest.

Fixing the Lighthouse

  1. After speaking to Larrisa go down south of her jumping across the basalt platforms and into the Barbarian Outpost.
  2. Talk to Gunnjorn (in the Barbarian Outpost Agility arena) and get the lighthouse key; you can get your two planks here, which respawn north east of Barbarian's Outpost.
  3. Use both planks on the broken bridge east of Larrissa.
  4. Go and talk to Larrissa again.
  5. Go up to the first floor. Search the bookcase and take all the books, flip through the lighthouse manual and the Ancient diary.
  6. Go up one more floor, use the following items on lighting mechanism in this order: swamp tar, molten glass, tinderbox.

The Door

  1. Go down the iron ladder into the basement to find the door.
  2. Use all of your basic elemental runes on the door (fire, water, earth, and air).
  3. Use your sword (any type, but you will not get it back), and your arrow (any type, but you will not get it back).
  4. If you hadn't, use your Games Necklace to go back to Barbarian Assault and bank there. There's no Barbarian Assault dummy, use any teleport and then come back here ( The closest teleport is to Rellekka either via Enchanted Lyre or House teleport, if your house is in Rellekka)
  5. Get your equipment. The Dagannoth Mother has high defense vs melee and ranged, but low magical defense and can be safespotted. You want anything that boosts your magical damage, so bring your best mage gear, a stack of air runes, any elemental staves/runes you have and the highest tier of catalytic runes (mind/chaos/death/blood) that you can spare.

The Fight

  1. Go through the eastern part of the door and down the ladder.
  2. Talk to Jossik, be prepared to fight two Dagannoths.
  3. The first one is easy if you have Protect from Melee. If you don't have Protect from Melee and your combat level is relatively low, it might be wise to safespot behind the rocks in the room. It can be killed by all forms of combat.
  4. Then right after you defeat it, there will be a cut scene, and you will fight a harder monster.
  5. You should attack the Dagannoth mother by color if you want to deal any damage.
Colour Type of Attack
White Magic: Air
Blue Magic: Water
Orange Melee
Brown Magic: Earth
Red Magic: Fire
Green Ranged
  • If you cannot see the color changes very well, look at the chat box. Using the wrong attack does no damage to it. Also, you can safespot her by using the stalagmites in the room. If you do it right, you can get the mother stuck behind a stalagmite where you can stand behind and not lose any health points.
  • The best way to defeat her is to ignore the ranged and melee forms, since her defence against those attack types is too high to be worthwhile. Either use an air staff and switch spell types, or switch your staves if you're quick and want to save up on elemental runes.
  • She can detect Prayer, and will automatically use the opposite attack type when you use prayer. By default, she ranges at a distance and melees up close. She can maul you for 24 damage so beware.

Getting your Reward

  1. You'll get a Rusty casket after you defeat the Dagannoth Mother.
  2. Go to the second floor of the lighthouse and show it to Jossik to finish the quest. (Note: If your inventory is full when killing the Dagannoth Mother you will not receive the casket. Instead go and talk to Jossik upstairs who will say he picked up the casket after you left it on the ground.)


  • 2 Quest Points
  • 10,490.6 Strength XP
  • 10,490.6 Magic XP
  • 10,490.6 Ranged XP
  • Access to the caves below the Lighthouse (contain level 74 and level 92 Dagganoths)
  • A damaged prayer book of your choice: Holy book (Saradomin), Unholy book (Zamarak), and Book of balance (Guthix). The other two books can be purchased from Jossik for 100,000 coins. All three give the same prayer bonus (+5) but slightly different offensive and defensive bonuses
  • Holy book gives a +8 bonus to all defensive stats, but no offensive bonuses
  • Unholy book give a +8 bonus to all offensive stats, but no defensive bonuses
  • Book of balance gives a +4 bonus to all offensive and defensive stats
  • These books are held in the offhand (shield) slot and only give their bonuses when they are completed. To complete the book, you must use the 'damaged' version with all four pages (found from clues).
  • If you lose your book, you can talk to Jossik to receive a replacement for 100,000 coins.
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