Although Gambit clearly wished to get back together with Rogue, he found himself unable to express his feelings for fear of her being killed by the green ghost that he had picked up in Antarctica. This "mist"-ery woman had developed romantic feelings for him and was jealous of his obvious affection for his Southern teammate. Moreover, for whatever reason of her own, she seemed to fear being discovered by the X-Men and further threatened to harm Rogue, if he told the team about her existence.
Rogue, nonetheless, guessed that Gambit's coldness towards her was based on more than bitterness about Antarctica and her suspicions were confirmed when she touched him accidentally, getting the briefest image of the ghost:
ROGUE: What the - ? Was that a hallucination or... ? I could find out - if I jus' hol' on a bit longer, but... .
GAMBIT (ASSUMABLY IN HER MIND): But dat wouldn't be right, chere.
Later, she confronted Gambit about what she saw, and, although he promised to tell her precisely what was happening with him, that conversation never materialised.
Eventually, however, the "mist"-ery woman was discovered by the team in Gambit '99 when Marrow accidentally stabbed him in the chest in a routine Danger Room session. The bone did not hurt him, the wound was completely sealed, and the X-Men obviously were mystified. By threatening him with a psiscan, Xavier eventually pushed him into undergoing tests at the hands of Moira, where the ghost was exorcised, as it were.
GML: A threat to you all, Xavier? That hadn't been my intention, though you will see I'm quite willing to... adapt.
GAMBIT: Nngg. *Haff*. Keep them out of this.
MARROW: Ouch. Well, leat the he\she or it has been narrowed down to two out of three.
ROGUE: Who are you?
GML: Nice to be among a group whose first reaction isn't "what are you?"
XAVIER: The what relates to what are you doing to Gambit? And should be addressed immediately after the first question.
GML: You are an ulcer waiting to happen, aren't you? As much as you presume you have a right to know but I prefer this matter to remain between Remy and myself. We had a deal. He is alive because I honored my end of the engagement. I intend to make sure he honors his!
Upset by what she saw as a breach of their agreement, the GML brought him to Manhattan, Indiana, where he managed to unearth the truth about her. It transpired that she was a girl by the name of Mary Purcell, who had supposedly died when she spontaneously combusted at a gas station. In reality, she had evolved into a form of life that was pure energy. After unsuccessfully trying to possess Magneto, who took her to study at his Antarctic base, she latched onto Gambit after his abandonment by Rogue. Her purpose? To make something worthwhile of her life by creating a new form of life with Gambit. Unfortunately, their "baby" would cost them both their lives and, obviously, he refused.
At this point, the X-Men intervened and managed to separate her from his body. However, because of the close connection between them, they could not stand the strain and both were in danger of dying:
GAMBIT: What should I do?
ROGUE: She's usin' you.
GAMBIT: An' I used her.
ROGUE: She's killin' you.
GAMBIT: An' I'm killin' her.
In an attempt to help her, Gambit charged a card and destroyed the device that had been used to separate her from him, but she was obliterated with it:
XAVIER: Her energy form was already severely compromised from the strain of her attempted biogenetic evolution.
GAMBIT: In English, I tried to save her and I ended up killing her.
Clearly upset by being unable to save her, by hurting her when trying to help her, Gambit went to lay flowers on her grave in Manhattan, Indiana. Knowing he would need some moral support and wanting to be there from him, Rogue followed him and it was there that she apologised for what she had done in Antarctica:
ROGUE: I'm sorry.
GAMBIT: I know.
ROGUE: No... I mean, for more'n Mary... for - for leavin' you behind.
GAMBIT: I know.
>
Unfortunately, although Antarctica seemed to be behind them for good, their problems as a couple were not...