- Pop into Magna's enormous mouth. After a quick cut scene with Robert you'll be free to explore. Start by opening the gem chest above your head to find two Damage Elixirs. Cross to the ledge on your left to find another chest, this holding three Quicken Elixirs.
- Descend into the pit, minding the lava coating Magna's throat on the way down. There's another gem chest along the way containing two Lull Elixirs. Fire drips and hops down here, so be careful as you make your way through Magna.
- You'll descend into an open area. Check to the right first. There's a pit of lava with several hopping fireballs on the adacent platform. Weave through the fireballs, open the gem chest in the middle of the lava for two Potent Healing Tonics, and kill the fire spider hanging on the right side of the pit. As you might expect, water does wonders in here.
- Pop open the chest beside the spider for two more Potent Healing Tonics, then descend and go left. After a quick cut scene you'll be standing in front of Magna's heart. A spider awaits inside, but you can't get at it yet.
- Head down and to the right of the heart. Descend past the dripping lava traps and the monsters along the way to find a gem chest halfway down, this containing two Damage Elixirs, and one of the huge spiders seeking Magna's heart at the end.
Gruesome. The Heart Spiders are very straightforward opponents, though admittedly strong at the same time. Appearing in clumps of three, they dominate the battle with normal attacks that will slow your characters on the Timeline. They're neither strong nor weak against any element, and consequently can't be easily manipulated. They're also very resistant to magic, so Finn is just about useless here.
Pull out Norah to counter their slowing effects and focus on one spider at a time, smacking down its HP until you only have two left, then one, then none. They're only a bit above the average spider in Magna, though that's bad enough, really.
- After beating the Heart Spiders, fly up and to the right of its former perch to find a chest. It contains a Tumbled Emerald. Grab it and return to the central chamber.
- Go down and to the left of the heart. There's a similar passage here, also leading to a Heart Spider mob. You'll find chests containing five Magic Defense Elixirs and two Faery Nectars along the way, and after killing the Heart Spiders you can grab Magic Defense Stardust and a Tumbled Sapphire.
- Return to the central chamber. Descend beneath the platform where you can investigate the heart to find an intersection. To the left floats Confession #9; to the right, Defense Stardust. Continue descending.
- There's another large chamber below. On your left is a chest containing two Rough Sapphires; on the right is a twisting passage full of falling fireballs and chests. Weave through here to find two Rough Emeralds, two Magic Potions, two Firefly Elixirs, three Lull Elixirs, and, at the end of the passage, Strength Stardust. Weave your way back to the previous chamber after collecting the lot.
- Keep descending. There's another split ahead. To the right you'll find the final Heart Spider mob, as well as a chest on a high ledge containing a Tumbled Emerald. To the left is a side quest that's most definitely worth doing.
Note: Until you complete this quest, Robert will leave your party. If you want him back you'll have to deal with the Bolmus Vault.
The Vault is protected by a combination lock with two phases. Start by activating the Vault. You can do this by pulling the two switches to your right and left twice apiece. This will match the symbols above the Vault door with the symbols on the door. That done, use Igniculus on the Oculi that begin revolving around the door. Once the Vault is open the quest will be complete, and you can open four chests inside the Vault. They contain two Revives, three Rough Rubies, a Rough Tourmaline, and two Faery Nectars.
- Got everything? Back to the central heart chamber. You can now investigate the heart and battle the final horrid monster plaguing Magna.
Now that's a biggun. Sir Spider is as brutal an opponent as he looks, and will force you into a long, gruelling battle. He's flanked by two normal Heart Spiders; make sure you take them out first and foremost. Their deaths will constitute just the beginning of the fight.
Sir Spider is a tricksy opponent thanks largely to his counterattack ability. If you hit him while he's charging, he won't do anything. Hit him while he's Casting, though, and Sir Spider will haste himself and any surviving Heart Spiders on the field. Consequently, you do not want to hit Sir Spider while he's in Casting mode. Either chip away at him while he's making his way to Cast on the Timeline or wait until he's unleashed his attack. Use the latter opportunity to heal your characters.
Sir Spider's other problematic attribute is his ability to paralyze his opponents, and he'll do this often. Consequently, you'll want to bring Robert onto the field fairly often. Have him heal anyone who gets paralyzed, them swap him out for a stronger fighter after both of your teammates are back on their feet. Norah is also quite helpful in this fight as she can remove Sir Spider's hasted status.
A long fight? Yes. Impossible? No. Sir Spider has no elemental strengths or weaknesses, and his high defenses will prevent you from inflicting considerable amounts of damage with anything besides high power magic. Expect this to be a gruelling brawl - though so long as you keep above 100 or so HP on both characters, staying alive shouldn't prove a major problem. Beating Sir Spider will earn you Dodge Stardust.
- There's a cut scene once the battle is done, and you'll be free to speak to Magna. She will send you off to your next destination, the Temple of the Moon.