Cara Pierce (aka April May or Maura Devon Carlisle) is the daughter of J. Rutherford Pierce and Debi Ann Pierce, and is the sister of Galt Pierce. She is an Ekaterina through her mother, Debi Ann Pierce, neé Deborah Starling. She is a major protagonist in Flashpoint and was also key to defeating her father, J. Rutherford Pierce.
Not knowing that Cara was actually April May, J. Rutherford Pierce hired her to track Amy Cahill and Dan Cahill. But then after seeing Pierce's men trying to kill Amy, she began to question her father's motives.
She is first seen when Galt beats her in a wrestling match. She is later seen when she spies on Pierce making their "energy drinks" (the serum in disguise), and switched her serum with Galt's after discovering that Pierce was giving her the weaker dose. While posing as April May, she discovers that Pony is hacking into her systems, and they have a friendly chat.
She beats Galt in a game of American History, made up by her father. She is later in Washington D.C. with Pierce, and slowly begins to realize Pierce's agenda; she finds out that Pierce had fired a reporter for commenting about the difference between democracy and dictatorship. She is kicked by Pierce; he also kicks a US Senator. Cara begins to realize that her father is losing his posture in public.
She and Galt interrogate Dan on Pierce's plane. The next day when they land in Cambodia she loosens the rope Dan is tied and gives him a detailed description of how to open the plane door so he can make an escape off the plane. It is later revealed to the Cahills and Pierce that she is actually April May. She helps the Cahills defeat Pierce after betraying her father after discovering his true motives. At the end of the book, she and Ian Kabra (technically Ian is the head of the family now) become the leaders of the Cahills.
Cara walks in and tells Ian that the Cahill meeting was moved. Then she comes at him feet first. It is revealed that she was going to kick Ian's tailor, because he had stuck Ian with pins dipped in a liquid that would slow him down. After they get kicked out of the mansion, they go contact Ham and Jonah, and go to Mont Blanc to find Amy and Dan, who have changed their last name to Swift. They decide that the disaster the Outcast mentioned is the Mont Blanc ship disaster, which took place in 1917. They go to Nova Scotia, and contact Atlas. He almost kills Ham, Ian, Dan, and Amy, who take Atlas's invitation to go on board the ship, which they believe will blow up. It turns out they were wrong, and they think the disaster is the Titanic II which will sail tomorrow. After getting on board the ship, Cara and Jonah have to stay behind. Dan meets Dr. Jeff on the ship, and he helps Dan. However, Dr. Jeff turns out to be the J.E.T. that stole research and turns out to be bad.
Cara, Amy, Hamilton, Dan and Ian are in Jonah's crib watching Jonah yell at his father about Silent Song, a movie he wants to make. Amy gets a text from Aunt Beatrice, which puzzles everyone. The text says 'look up', and the Cahills obey. There is a dirigible floating overhead, and a poem by William Carlos WIlliams is repeating on the dirigible. The Cahills follow it. Since they believe that the Outcast is trying to recreate the Hindenburg, they go to the landing site, where a incendiary device blows it up. Hamilton points to a billboard, that shows a contest in which dirigibles compete, and Cara informs the Cahills that the bomb is one favored by the KGB and Russian mafia. Each person climbs on a different dirigible, and everyone is presumed safe, until Ian reveals that he had a brief encounter with his father. Amy squeezes his hand, showing that she still likes him as a friend. They go on board a MIT ship, and Eriele, a Lucian, tasers Cara, but Eriele gets tasered herself later. Everyone believes they are going to die, when the other airship explodes. Cara is last seen in a car with Amy, Dan, Ian, Ham, and Jonah. The Outcast's identity is revealed.
After her and the rest of the Cahills regroup in Jonah's home in Lake Como, she goes to Amsterdam, with Ian, and Dan to stop the flood that the Outcast is planning. While Dan learns more about the city, her and Ian research about all the dams in the area, but can't figure out which one the Outcast will hit. After a meeting with the mayor, they figure out the dam they need to go to is Maeslantkering, and head over there as quickly as possible. Once there she hacks into the dam's control center to close the dam, while Ian and Dan evacuate people. She is able to close the dam just in time.
Cara hacks Nathaniel's facial recognition software so that it is harder for him to catch Dan, the only person alive who knows the serum. She goes with Ian to visit a Dr. Peerless at the Imperial College in London, however they both discover he was killed by Alek Spasky. Her and Ian chase after Alek, following him to Kiev and then to Chernobyl where they discover him mourning over his wife's grave. After being chased out of Kiev when Ian's informant betrays them, Cara and Ian travel back to Grace's mansion to stop the Outcast's party. Her and Ian originally believe that the sorbet being served at the party is poisoned, however when Cara is forced to eat some, they realize that is wrong. They discover the Outcast's anti-Cahill bee plan and save the rest of the Cahills at the party from being killed by the bees. Some time after the events of this book her and Ian start dating.
After helping Dan and Amy with their mission at the start of the book, she and Ian, Jonah and Hamilton all travel to Berkeley, England to Sinead's former home. They all get into an altercation with Mr. West's hired goons, and Hamilton, Ian, and Jonah all end up infected with the Dancing Goat Pox. She helps them fly back to Attleboro to get help, but she eventually ends up infected too. She along with the others are flown to the Bermuda Triangle Ekaterina Stronghold to receive help from Dan, Amy, Dr. Miller, and Sinead. Eventually she along with the others receive the vaccine, and complete their mission.
- April May is the fake name Cara uses online.
- She has taken weaker forms of the Janus Serum and the Tomas Serum, but both were invalidated by the antidote.
- She has an interest in Ian Kabra.
- At the end of Mission Atomic, it looks like Ian Kabra and Cara are now together.
- In Mission Atomic it mentions that she was once stung by a bee this lead to her being in a hospital for two days. This may indicate that she has an allergy to bees.
- Cara is said to have clear green eyes, chin length blonde hair, a heart shaped face and pale skin.