"Trust me, Khaleesi." — Jorah Mormont
"It's you I should trust, Ser Jorah? Only you?" — Daenerys Targaryen
The Mother of Dragons might be surprised to learn that her "most trusted advisor, most valued general, and dearest friend" Ser Jorah Mormont, who has been at her side since her wedding day, was actually once a spy for the men ruling Westeros, the kingdom she wishes to conquer. But to viewers paying close attention, this is no surprise, as characters on the show have discussed it many times. The only question is, when did he stop spying? When did his betrayal turn to love?
As he's repeatedly admitted, Jorah caught men poaching on his land on Bear Island, sold them into slavery to pay off his debts incurred by trying to keep his wife in the lifestyle she was accustomed to, and was sentenced to death by Ned Stark. Had he not fled his home of Bear Island, Jorah would have been executed by Ned himself. (The late lord believed that was his duty, as we learned in episode one, season one). "I wouldn't be here to help you if Ned Stark had done to me what you want to do to the masters of Yunkai," Jorah recently reminded Dany. But fleeing Westeros to go live in exile brought dishonor to his house, which is why his sister had to step up (the warrior woman glimpsed in Robb Stark's war councils) and why his lord father, the late Lord Commander of the Night's Watch Jeor Mormont, had a spare Valyrian sword to give Jon Snow. (When the Old Bear gave it to Snow, he said, "It was meant for my son Jorah. He brought dishonor to my house, but he had the grace to leave the sword.")
In exchange for a royal pardon, Jorah thought he could do some simple spying for Varys on the Targaryens' movements, and then go home. ("What do you pray for, Ser Jorah?" Khaleesi once asked him. "Home," he answered honestly.) So when Dany and Viserys arrived in Pentos, when they planned to marry her to Khal Drogo, and when the wedding took place, he sent letters to Varys. King Robert got a note with the news, which he shared with Ned. "Daenerys Targaryen has wed some Dothraki horselord, what of it? ... This Khal Drogo, it's said he has a hundred thousand men in his horde." If Jorah was the provider of this intel, he may have exaggerated, since Drogo's horde was actually 40,000 at the time. But why? Did he want them to take the intel more seriously? Or scare them a bit? And when Ser Jorah learned that Khaleesi was expecting, he immediately leaves the horde to ride to Qohor, without saying why. Soon, Varys got "disturbing news from far away."
"The whore is pregnant," King Robert told the Small Council. "I want her dead. Mother and child both. And that fool Viserys as well, is that plain enough for you?"
"You want to assassinate a girl because the Spider heard a rumor?" Ned asked. "Based on whose information?"
"Ser Jorah Mormont. He is serving as advisor to the Targaryens," Varys said.
"Mormont?" Ned asked with indignation. "You bring us the whispers of a traitor half a world away and call it fact?"
"Slaver, not a traitor," Littlefinger corrected him.
"He broke the law, betrayed his family, fled our land," Ned said. "We commit murder on the word of this man?"
Ser Barristan Selmy might have known all of this, had he actually sat on the Small Council on the show as he does in the books. But as he pointedly told Jorah, he didn't get intel about "backstabbings and betrayals." This Council conversation, however, was the turning point for Ned Stark, and caused him to quit as King's Hand. And it was the turning point for Jorah Mormont, because he did not anticipate that his spywork would or could lead to Dany's death. Riding with the horde, serving as advisor and protector to the Targaryens (more so for Dany), he started to care about her. When she wearied from horseback riding, he called her "child," offered her jerky to eat, and some empathy regarding her rough start to her marriage. When she learned to command, he responded with respect and called her "a queen" and "khaleesi." Even Viserys noticed that Jorah's attention seemed somewhat romantic, but the letters continued — he sent word after Viserys's death, as he said in his confession.
Still, Jorah didn't seem to be worried for Dany's welfare, until he got a message from the Spider at the western market: "A royal pardon. You can go home now." And then Jorah knew why — because they were planning to assassinate Dany. He managed to thwart one attempt (poisoned wine), but he knew there would be more, and told her so: "King Robert will never leave you alone. If you sail all the way to the Basilisk Isle, his spies will tell him. He will never abandon the hunt." (He didn't tell her, however, how he knew).
When Khal Drogo was dying, and her child was stillborn, Jorah tried to get her to run away with him, to the port of Asshai. He may have already loved her then. But when she emerged from Khal Drogo's funeral pyre with her baby dragons, he worshipped her. "Blood of my blood," he called her. And later, he told her in awe, "There are times when I look at you, and I still can't believe you're real." It's likely he never sent another letter to King's Landing after season one — because when asked if he would betray the Khaleesi again by the masked woman in Qarth in season two, his response was, "Never." And this is seemingly confirmed when Maester Pycelle asks the Small Council if Mormont is still spying on her for them. "No longer," Varys said. "He appears to be fully devoted to her." (This response prompted Tywin to out him, since Jorah was no longer useful, and Dany was a growing threat). Will Jorah be as devoted to her if he's in exile for the second time?