Before going through the exit, get the last Treasure (30/30) from the vase in the far left corner. Also, pick up the Health Potion from the right hand side. Do not leave just yet, because the Relic is in this room. (If you are not interested in getting the Relic, skip to the part of the walkthrough Through the exit.)

Getting the Relic - In order to get the Relic, you have to challenge yourself against a timed running. It is not difficult, but you will most probably try more than once. Do you remember the glowing symbols you met on the various ledges until you came here? There is one more on the pillar to the left of the exit (this screenshot shows the location).

There are six waterfalls in the room; three on each side. You have to activate all four symbols in order to stop the flow of the middle waterfall on the left when facing the entrance. Near the waterfall is a metal ring that will help you swing to the alcove behind the waterfall where the Relic is. (This screenshot shows the waterfall and the metal ring). The catch here is that each symbol remains active for a little while, so you have to run and activate the next symbol before the previous one turns off.

The timed run - (The entire process is shown in this page.) Go to the first symbol which is located to the left of the exit (as you face it). Press the Interact button to activate it and make it glow. Turn right and sprint to the extended ledge above the toxic pool. Just before reaching the ledge, release the Sprint button and steer Lara a bit to the left. Keep running and jump towards the pillar with the second symbol. Lara will hit on the pillar and slide to the ledge below losing some health. However, you will land in front of the second symbol, so press the Interact button to activate it.

Turn right and jump over the toxic pool to land on the opposite ledge. Run forward and jump to grab the tall vertical pillar. Climb to the top, tapping the Interact button at the same time to make Lara climb faster. When you perch on the pillar, jump to the ledge ahead.

When Lara pulls up on the ledge, do not move forward. Instead, make a "blind jump" to land on top of the next tall vertical pillar beyond the ledge. If you move forward on the ledge, Lara will bypass the pillar and end up in the toxic pool.

Aim for the middle part of the low wall on the left before jumping there. If you jump towards the left part of the wall (the one that is closest to you), Lara will bypass the wall and end up in the toxic pool behind, because the distance is small. In case you land on the wall, step backwards to hang from from it. Then traverse to the very right, tapping the Interact button to make Lara move faster.

Jump to the small vertical pillar behind you, then to the ledge beneath the entrance.

Turn right and approach the edge of the ledge. Jump on the pipe and make two consecutive jumps forward to cross the pipe quicker. Then jump to the ledge ahead. Activate the third symbol and jump back to the pipe. Again, make two consecutive jumps forward to cross the pipe and jump to the ledge beneath the entrance. Run forward and jump to grab the tall vertical pillar. Climb to the top, tapping the Interact button at the same time to make Lara climb faster.

Once you perch on the pillar, turn right to face the ledge and jump to it. Then sprint to the pillar to the left of the entrance and activate the fourth symbol.

Turn right and sprint back to the ledge you came from. Just before reaching the ledge, release the Sprint button and run to the right side. Jump to land on top of the tall vertical pillar and then jump to the low wall ahead. Lara will grab onto it, so traverse to the left as much as you can (until Lara is hanging from the corner). Jump to grab the tall vertical pillar behind you and climb to the top. Once again, jump to the ledge ahead but this time turn right.

If you have made it on time, there should not be any falling waterfall ahead. Use the Grapple to catch the metal ring above and jump forward. Swing a couple of times to gain some momentum and jump to grab the edge of the alcove. Pull up and get the Relic.

Use the Grapple to catch the same metal ring and swing back to the ledge. Then make your way back to the exit. If you happen to die before reaching the exit, the Relic will still be on your backpack, so do not worry.

Through the exit - Go through the exit and follow the hallway. When you reach the corner, pick up the Health Potion on the right. Continue down the hallway and turn right around the next corner. Slide down the slope and equip the Hammer. Four Viking thralls will turn around the next corner, so take care of them.

Approach the corner they came from and be prepared for the next battle. Twenty Viking and three Yeti thralls will attack. Use the Hammer and quickly start shooting before they reach you. Aim for the Yetis first because they can do the most damage and kill with one shot any Viking thrall that approaches. You can also use a sticky grenade, but make sure you throw it to the wall and not to the thralls because they can carry it back to you!

When the fight is over, continue through the hallway and when you reach the next corner, pick up the Health Potion from the left. Go to the right and follow the hallway to the next room.

The cut scene shows Lara entering the next room. She takes a look at the feminine figure that is standing in front of a falling water and recognises the silhouette. "Mother?" shes asks. As she approaches the woman she continues "Mother? It's me. It's Lara." The woman turns her head towards Lara and it's Amelia Croft, Lara's mother. But when she turns around, Lara steps back and cannot believe in her eyes. Her mother has turned into a thrall after all these years trapped in Helheim. Amelia approaches her, but Lara is trying to convince herself that her mother is dead so as to take the difficult decision. She points her gun towards her mother and says "My mother is dead. My mother died a long time ago." She takes a final look at her mother and says "You're not my mother." Just before Amelia reaches her, Lara Lara shoots the thrall until it falls into the toxic pool.

Lara kneels, obviously disappointed from the result. Natla arrives and confesses that she set Richard Croft on a quest to search for his wife so she could find the way to Helheim. But he betrayed her in Thailand and she killed him. When Lara appeared with Thor's Gauntlet, she used her in order Lara to continue her father's job which would lead Natla to Helheim. Lara takes out Mjolnir, the only weapon that can stop Natla. Before she uses it, the doppelganger appears from behind and grabs her, knocking the Hammer out of her hands.

"When I made this creature for Amanda," Natla explains, "she had no idea that my true purpose was to have the means to destroy you at this very moment." She also admits that both Lara and Amanda were mere actors in her play. She has a serpent to raise, so she leaves.

Lara and her twin start to fight, but the doppelganger throws Lara on the floor and grabs her neck. As she tries to choke her, Amanda appears from behind and uses the power of Wraith Stone to stop the creature and throw it into the toxic pool. Lara is amazed, but Amanda comes to explain that she wanted to let the creature finish Lara off, but the Midgard Serpent will tear the world apart and the only thing that can stop the disaster is Thor's Hammer.

Three Yeti thralls come from the hallway and Amanda tells Lara to go for the job since she can hold them off. Amanda tries to stop them and Lara is now after Natla.

After the cut scene, equip the Hammer (yes, you still have it!). Kill the two Viking thralls and continue through the hallway. As you turn around the next corner, a Yeti thrall appears, so take care of it. Pick up the Health Potion from the right hand side of the corner and follow the hallway. Slide down the slope and before reaching the end, jump over the pit that contains toxic water.

Follow the hallway and deal with one more Yeti thrall at the end. Then follow the hallway to the next area with the big structure. Drop down to the lower ledge and head to the other side. Go down the stairs and cross the walkway.

In the cut scene, Lara walks to the circular walkway ahead and spots Natla above. She throws an energy bolt to attrack her attention and orders her to shut the device down. Natla seems surprised that Lara made it through here, but it is a good chance so that Lara can see firsthand "the fruits of her labor".

Lara asks if this is the Midgard Serpent and Natla says "Of course not. Jörmungandr is the network of tectonic ridges that encircles the earth of the ocean floor." And she explains that when this relic unleashes its fury below, the very seams of the planet will burst. Natla then quotes the Eddas to Lara. "The Midgard Serpent will rise up and spew poison into the air, and all the world will be consumed by fire and ash."

Natla sets the device into motion and shouts "Ragnarök! The seventh age is upon us!" The camera then shows four angled supports, each one having a mechanism at the bottom. Natla knows that Lara is here to stop her, so she throws a fireball at her, but Lara manages to evade.