Take Up Arms

This is the first quest within the Companions quest line. This quest consists of training with Vilkas, giving Vilkas' sword to Eorlund, bringing Aela the Huntress her shield, and following Farkas to the guild quarters.

Train with Vilkas
To train with Vilkas, follow him out to the courtyard. If the Dragonborn happens to lose sight of him, the Dragonborn can find him outside practicing with one of the target dummies until the Dragonborn arrives. Speak with him and he will tell the Dragonborn that the "old man" told him to have a look at the Dragonborn. He will then instruct the Dragonborn to take a few swings at him so he can gauge the Dragonborn's skill. Vilkas will draw his sword and shield but refrains from attacking the Dragonborn, so swing away. After about three swings, and a few humbling remarks, this part of the quest ends with Vilkas handing the Dragonborn his sword to bring to Eorlund Gray-Mane. The Dragonborn can't use magic against Vilkas, unless the Dragonborn uses Bound weapons. Vilkas may remark on you using magic if you use an enchanted weapon and will fight back until the end of the training. This may be a glitch.

Note:  If you are wearing Ebony Mail Vilkas will not fight because of the poison effect of the Ebony Mail, which counts as magic.

If the Dragonborn waits too long and has grown too powerful (very strong weapons) the Dragonborn can kill him in 1 hit, which will result in him trying to kill the Dragonborn even after the Dragonborn completes the quest. Killing him in 2 hits results in him calling the Dragonborn mightier than he/she looks rather than the usual dialog.

Also, a random glitch may occur where Vilkas will become aggressive as soon as the Dragonborn goes outside for their training. This is probably caused by having a follower attack him without the Dragonborn noticing. As such, it is suggested not to bring a follower with the Dragonborn on this particular quest.

Give Vilkas's sword to Eorlund
Eorlund Gray-Mane is found right next to the courtyard, up some stairs and next to the Skyforge. A gruff and straightforward man, he asks the Dragonborn what brings them to the skyforge. Once the Dragonborn explains that Vilkas sent the Dragonborn with his sword, he rightly assumes the Dragonborn to be the newcomer and softens a bit. He even offers some sage advice; don't always do as they are told. No one rules anyone else in The Companions. Eorlund states that he is not a Companion, but since no one else can work the forge, he is honored to help them out in any way he can. He voices a bit of surprise that they have lasted as long as they have without a leader but with Kodlak as Harbringer and advising the Circle, they succeed and yet each man is his own and each woman is her own. As the Dragonborn is about to take the their leave, he asks a favor of the Dragonborn; to take Aela's shield to back her as his wife is in mourning. Once the Dragonborn accepts, he hands over the shield to the Dragonborn, ending this part of the quest.

Bring Aela her shield
Leave the Skyforge and head back to Jorrvaskr. Head down to Jorrvaskr Living Quarters, where the Dragonborn will find Aela the Huntress in her room conversing with Skjor. Approach her, and once the Dragonborn hands over her shield she explains that she's been waiting a while for its completion. It takes a moment but she recognizes the Dragonborn from the giant fight at the farm. Skjor makes mention that he saw the Dragonborn training in the courtyard with Vilkas, where Aela heard the Dragonborn gave him a good thrashing. Now Aela wonders if the Dragonborn could take Vilkas in a real fight. If the Dragonborn answer with the second choice, she explains that shield-brothers do not kill each other over a dispute. She seems impressed with the passion that burns in the Dragonborn, noting that the Dragonborn would make a fierce Companion. They call out for Farkas to show the Dragonborn where they will be staying and completes this part of the quest. Note that the Dragonborn cannot drop the shield. So if the Dragonborn venture off to do other things, they will not be able to rid themselves of any Steel Shields they collect.There is also a glitich where it says Aela is at Bleakwind Basin and she is not in her room nor at Bleakwind.

Follow Farkas
Follow Farkas as he shows the Dragonborn to the their room. After some small talk, he tells the Dragonborn to pick a bed and fall in it. He expresses that he is pleased to see a new face and if the Dragonborn is looking for work, come see Aela or himself. Once the Dragonborn start making a name for themselves, he tells the Dragonborn to see Skjor or Vilkas for additional work. This completes the quest and the Dragonborn will unlock the Take Up Arms achievement.

Before the Dragonborn part ways, Farkas will tell the Dragonborn about some trouble they're having in Whiterun Hold. This is most usually a problem with the Falmer, and if the Dragonborn accept the job, this will start the quest Trouble in Skyrim. A different quest may be assigned if Shimmermist Cave was cleared.

Bugs

 * When you try to give Aela's Shield to Aela, she won't talk to you. This happens when the Dragonborn tries to talk to her while she's talking to Skjor.
 * Solution: Exit Jorrvaskr then come back, the shield can be retrieved from Aela again.
 * There are some instances where the quest indicator marks Aela at the Giant Camp west of Whiterun, but she's not there. To get to her, you must use the plate through wall glitch in Whiterun, and head to her location , however when you choose the option to give her the shield , nothing will happen and you will be locked of speech with her, making the rest of the companion's questline impossible or , she may still be in one of the farms, where the Dragonborn spot the Companions killing a Giant after escaping execution.
 * Solution: If the Dragonborn can't find her, open the console and type . This causes Farkas to walk downstairs and show the Dragonborn to their lodgings, opening the next quest stage.
 * Another solution is to type in the console prid 0001a697. This will select Aela wherever she is. Then type recycleactor. Now Aela will be in her room in Jorrvaskr waiting for the player. For this scent to work also do Skjor, 0001a691,  then recycleactor.  Now the Dragnborn can proceed with the quest as normally would.
 * Optionally, type  to place Aela near the Dragonborn so the Dragonborn can giver her the shield. This does not complete the quest, nor will it trigger the conversation between her, the Dragonborn, and Skjor.
 * Solution: Using the plate through wall glitch go out to her location then hit her while unarmed to get her to turn hostile. While she is hostile slowly make your way back toward the main gate to Whiterun. Once there wait until she is relatively close by and then use the gate to travel to Skyrim. Being hostile she should follow you within a few seconds, be sure to sheath your weapon so when she comes through the gate she stops being hostile. From there her ability to navigate the world is restored to normal and you can either give her her shield there or wait for her to return to Jorrvaskr.
 * Occasionally during the quest point 'Bring Aela her shield' the player character will return the shield, removing it from their inventory, but Aela will not receive it, and the player character will not be able to progress further in the companions questline. If you attack Aela after she "takes" the shield, the quest will show as completed, though now you have to run out and find a guard to punish you for your crimes, otherwise the Companions will continue attacking you. Sometimes you won't get a bounty though, and the guards will attack the Companions. If this happens then kill all the guards and the Companions will become peaceful. Afterwards you can go back and continue down the questline.
 * Easiest solution is to open the console and type
 * Another solution is to simply go to another floor in Jorrvaskr, then immediately return to Aela. If she begins talking as soon as you get to her, the quest will continue.
 * Attacking Aela can cause another bug in which you cant talk to the guards about the crime. If you enter Dragonsreach the whole city will turn hostile. If you leave Whiterun instead and re-enter the city, all companions will be peaceful again and you can continue the quest.

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