Horror from the Deep Quest Guide
OSRS Horror from the Deep walkthrough, requirements and rewards
Updated September 2026
Horror from the Deep unlocks the Lighthouse and its Dagannoth caves, rewarding a damaged god book of your choice. It needs 35 Agility and completion of Alfred Grimhand's Barcrawl.
On this page
6 sections
Overview
| Difficulty | Intermediate |
| Length | Short |
| Quest points | 2 |
| Series | None |
| Start point | Talk to Larrissa outside the Lighthouse north of Barbarian Outpost. |
Requirements
Skill Requirements
| Skill | Level |
|---|---|
| Agility | 35 |
Other Requirements
- Completion of the Alfred Grimhand's Barcrawl miniquest
- Ability to defeat the Dagannoth Mother, who cycles damage types
Items Needed
- Fire, air, water and earth runes
- Any sword or longsword you are willing to lose
- Any arrow (not ogre or training arrows)
- Molten glass
- Tinderbox
- Hammer
- 60 steel nails
- 2 regular planks
- Swamp tar
Recommended
- 40 Prayer for Protect from Missiles
- Combat level 50 with armour and food
- 13 Magic+ to cast each elemental spell
- Fast travel to the Lighthouse and Barbarian Outpost
Walkthrough
Video walkthrough by Slayermusiq1.
- Start at the Lighthouse. Travel to the Lighthouse north of the Barbarian Outpost and talk to Larrissa.
- Repair the bridges. Run east to the second bridge and use a plank on it, jump across, then use a second plank on the far side.
- Get the key. At the Barbarian Outpost Agility arena, talk to Gunnjorn for a key after completing the barcrawl, then return to Larrissa.
- Light the beacon. On the lighthouse roof, use swamp tar, a tinderbox and molten glass on the lighting mechanism. In the basement, use one of each elemental rune, a sword and an arrow on the strange wall.
- Defeat the Dagannoths. Open the eastern strange wall, climb down and talk to Jossik, then kill the level 100 Dagannoth and the Dagannoth Mother using the elemental spell matching her current colour.
- Claim your book. Take the rusty casket to Jossik upstairs to receive a damaged prayer book.
Rewards
- 2 Quest points
- 4,662.5 Magic, Strength and Ranged experience
- A damaged god book of your choice, upgradable to a Holy book, Unholy book or Book of Balance
- Access to the Lighthouse general store and the Dagannoth caves
- Dagannoth Mother accessible in the Nightmare Zone
Related Quests
Related Tools
Horror from the Deep FAQ
01What are the requirements for Horror from the Deep?
35 Agility (boostable) and completion of Alfred Grimhand's Barcrawl, plus the ability to defeat the Dagannoth Mother.
02How do I damage the Dagannoth Mother?
She cycles every 18 seconds between being vulnerable to one damage type. Watch her colour and use the matching elemental spell, Ranged or Melee.
03Which god book should I choose?
You can choose the Holy book (Saradomin), Unholy book (Zamorak) or Book of Balance (Guthix). The others can be bought from Jossik for 5,000 coins each.
04How long does Horror from the Deep take?
It is an Intermediate, Short quest, though completing Alfred Grimhand's Barcrawl to start it can take a while.
05Is Horror from the Deep worth doing?
It unlocks the Lighthouse and Dagannoth caves, gives 4,662.5 experience in Magic, Strength and Ranged, and is required for the Culinaromancer section of Recipe for Disaster and the Medium Fremennik Diary.
06Can I safespot the Dagannoth Mother?
The Dagannoth and Dagannoth Mother can be safespotted, and with Protect from Missiles you can negate all of the Mother's damage while switching attack types.
07Can I boost Agility for Horror from the Deep?
Yes, 35 Agility is boostable, but completing Alfred Grimhand's Barcrawl is required to start the quest.
Next Quest
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Darren started playing the original RuneScape 2 back in the day and came back when Old School RuneScape launched. He's played on and off over the years and built OSRSToolkit to give players a single place to find reliable tools, calculators, and guides — all informed by real in-game experience.