Alexendra Jensen, commonly known as Alex, is an American, member of the Kentucky Irregulars, and the pilot of an Agusta A109 helicopter. After the destruction of the Irregulars by the male dragon, she moved to Quinn's Castle and lived with him and his people.
Alex was introduced shortly after Denton Van Zan and the Kentucky Irregulars were allowed inside Quinn's Castle by Quinn Abercromby. She flew overhead, showing off to the people and proving that the air was not just the dragons' territory before landing. When the castle was attacked by the Female Dragon that had recently burned their crops and killed several of their people, Alex took off with a crew of three "jumpers."
Due to the thick cloud cover, the dragon was able to ram the chopper, forcing her people to jump early to try to net her. Two of her crew were subsequently killed (one eaten, one crashed into the ground) when the dragon freed itself from the nets. She was disgusted by the party held by Quinn's people after the female dragon was killed, having lost three of the Irregulars to kill it, and she being just one of hundreds of dragons.
Van Zan gave Alex the dog tags of the three men they lost, explaining to Quinn that she was the Keeper of the Dead and that when all this was over she would build a wall listing the names of those killed. She and Van Zan explained to Quinn that all the dragons they had killed were female and that there was probably only one male dragon to fertilize the eggs. Since female dragons only live for a few months because of their high metabilism, if they could kill him they could end the dragon species. Quinn refuses to help since the male dragon had killed any group that had went after it before and fearing that might track the group back to the castle and attack it.
When Quinn learns that Van Zan is recruiting his people after he told him no he becomes enraged and attacks the Irregulars' leader. He easily loses the fight, but Alex gives him some Iodine before they leave, telling him that it hurts like hell but can clean his wounds. Alex is not present with the other Irregulars when the male dragon eliminates them, presumably she is off scouting with her chopper and is not able to return in time.
She and Van Zan return to the castle with one other survivor only to find it in ruins after the male dragon's attack. They dig the survivors out of the bunker, and Quinn finally agrees to help them kill the male dragon. Alex flies them to London in her chopper and Quinn leads them to the male dragon's lair.
They attack the male dragon with crossbow bolts tipped with a magnesium and C-4 explosive charge, but Van Zan's arrow misses and Alex sees him be eaten by the male dragon. She later distracts the male dragon by shooting and running in front of him while Quinn finds the arrowhead he dropped. He is later able to kill him.
Several months later, Alex is seen with Quinn and other survivors erecting a radio antennae near the North Sea. There have been no dragon sightings in three months. Jared rides up to tell them they made radio contact with another group of survivors in France, and that they who wish to speak to their leader. Alex seems pleased when Quinn tells Jared he is now the leader, announcing his dedication to rebuilding.