Gallus, along with Mercer Frey and Karliah, was a member of the Nightingales. Sworn to protect the Shrine of Nocturnal, she blessed him with extraordinary skill. Gallus was in a romantic relationship with Karliah.
One night, Gallus was caught breaking into a laboratory owned by Enthir. Before he could call the guards, Gallus made a comment that intrigued Enthir. The two struck up a conversation, and eventually became dear friends. When asked why a scholarly man such as Gallus would turn to thievery, Enthir made a suggestion that Gallus always felt more comfortable breaking in through a window than he did bent over dusty tomes.
Unfortunately, Gallus met his end after being lured to a remote location by Mercer Frey, who then murdered him. Mercer dumped his body into a nearby crypt, and framed Karliah for the killing, who was forced to flee. However, Karliah was eventually able to reconnect with the Guild through the Dragonborn, after Mercer's betrayal of the Guild became known. She rejoined the Guild and worked with them to avenge Gallus.
In death, Gallus fulfills his contract with Nocturnal to protect the Twilight Sepulcher as a Nightingale spirit. The Dragonborn encounters Gallus while attempting to return the Skeleton Key. Gallus informs them that all of the Nightingales are losing their connection to Nocturnal, which has caused the remaining guards to become hostile. Gallus claims that he too, will soon lose his connection to Nocturnal if the Skeleton Key is not returned.
After the Skeleton Key has been placed in the Ebonmere, Gallus and Karliah are reunited, but briefly. Gallus tells Karliah that they will be together again when she is called to serve Nocturnal in her realm of Evergloam.
Gallus is encountered in the first room of the Twilight Sepulcher during the quest "Darkness Returns". He appears as a Nightingale Sentinel and will approach the Dragonborn. Once his true identity is revealed, his name changes to Gallus.
"I don't recognize you, but I sense that you're one of us. Who are you?"
I'd ask the same question of you: "The last of the Nightingale Sentinels, I'm afraid. I've defended the Sepulcher alone for what seems like an eternity."
The last? What happened to the rest?: "We were betrayed by one of our own kind. In fact, I'm to blame for what's happened here."
How are you to blame?: "I was blinded. Blinded by dark treachery masquerading as friendship. Perhaps if I had been more vigilant, then Mercer Frey wouldn't have lured me to my fate and stolen the Skeleton Key."
Wait a moment... You’re Gallus!: "I haven't heard that name in a long time. How do you know of me?"
I have the Key: "The Key! You have the Skeleton Key! I never thought I'd see it again. And Mercer Frey?"
Dead: "Then... it's over and my death wasn't in vain. I owe you a great deal, Nightingale."
Three possible options are presented, of no particular consequence:
- I did this to honor the Guild: "You've done the Guild a great deed. And although they may not show it, I'm certain they appreciate your sacrifices. My only regret is that you had to undertake this task alone."
- I did this to get rich: "Were I able to provide it, I'd shower you in wealth for what you've done. My only regret is that you had to undertake this task alone."
Karliah helped me: "Karliah... she's still alive? I feared she'd befallen the same fate, ending up a victim of Mercer's betrayal."
Then take the Key and right all the wrongs: "Nothing would bring me more pride than to return the Key, but I'm afraid it's impossible. From the moment I arrived here, I've felt myself... well... dying."
How can a spirit die?: "The Sepulcher isn't merely a temple or a vault to house the Key. Within these walls is the Ebonmere... a conduit to Nocturnal's realm of Evergloam. When Mercer stole the Key, that conduit closed, severely limiting our ties to her."
Then I'll have to proceed alone: "I'm afraid so. I'm weakening, and I can feel myself slipping away. The years without restoration of my power have taken their toll. Whatever damage has been caused can only be corrected by following the Pilgrim’s Path to the Ebonmere and replacing the Key."
If a response times out, or when the conversation ends, he will say, "Good luck, Nightingale."
The next set of dialogue options becomes available and can be asked repeatedly until completing the quest:
- Luck is meaningless. What we do involves skill: "Yes, absolutely. Your skill is your own... don't let anyone ever tell you otherwise. But Nocturnal, she influences our luck; nearly imperceptible assistance we get when we ply our trade."
- How's that changing the way things are?: "Think about the Guild... about the state it was in when you began. Think about all the little things you might have heard. A pick breaking when it shouldn't have, the clouds in the nighttime sky clearing at the wrong moment... Our access to those bits of luck are what separate us from common bandits."
- So with the Ebonmere closed, our luck's run dry: "Precisely. There are a few who still call Nocturnal “Lady Luck” and for good reason."
Can't you just take the Key?: "Whatever is affecting the Nightingale Sentinels is starting to affect me too. As I get closer to the Ebonmere I begin to feel myself slipping away. Even right this moment, I feel strange... when I don't think I should be feeling anything at all."
What's wrong with the other Nightingale Sentinels?: "With the Ebonmere closed, and their sudden severance from the realm of Evergloam, I fear they've undergone a drastic change. They're shadows of their former selves. They no longer remember their true purpose or their original identities."
- Why aren’t you like them?: "My spirit didn't manifest itself in the Sepulcher immediately, so fortunately I wasn't present when the Ebonmere was sealed. However, ever since that day, I've felt my power waning... slowly draining away."
Selecting the following dialogue will start an optional objective to retrieve Nystrom's Journal:
- He can be pickpocketed but he has no items. If attacked in melee range, he will run to pick up a nearby pickaxe which will then be in his inventory.
- If the Dragonborn attacks Gallus while in beast form, he will be sent flying across the room. This has no relevant effect other than making him engage them in a brawl. If very patient, Gallus' punches can be used to increase armor skill levels.
- Gallus is Latin for rooster.
- He is the author of the books The Nightingales Vol. 1 and The Nightingales Vol. 2.
- Gallus was voiced by Craig Sechler.
- It is likely that the lone skeleton in the final room of Snow Veil Sanctum (only viewable if the Dragonborn re-enters the Sanctum) is in fact Gallus, since his body was dumped into the ruins and the skeleton itself is below a skylight.