Scarlett McKenzie was a lounge singer. Initially she was a singer for Doc Neutron in a cantina outside Ensenada. Her employment came to an end when Prelates Havok and Sabretooth crashed the establishment. Scarlett attempted to kill Havok since he had come to kill her meal ticket, but she failed. Scarlett survived and later became a spy for the Human High Council, using her singing talent to secure a position at Heaven a bar owned by Angel that was a neutral ground for mutants and humans alike.
She reconnected with Havok and became his lover even though such relationships were against the law in Apocalypse's domain. Scarlett found it easy to milk Havok for information because he was a braggart and he was jealous of his brother Cyclops. When Karma (another operative of the Human High Council) was captured by the forces of Apocalypse, Scarlett began to fear that she might be next to be discovered.
She soon found that she had become pregnant with Havok's child, and shortly after this realization, she was outed as a spy. The Bedlam Brothers came and arrested her, taking her to the Slave Pens. Furious at being used, Alex interrogated Scarlett over her spying on him, and she revealed that she was pregnant. Since this would ruin his chances of replacing his brother, Alex found it difficult to believe. Before they could say anymore to each other, the power went out.