While investigating the death of an Irish mobster, Beckett and Castle uncover a local turf war that may be connected to both a late-night infomercial guru and an international drug smuggling operation. But the case turns agonizingly personal when evidence emerges that the killer they're chasing may have had a hand in Beckett's mother's murder.
Mysteries abound when a family returns from vacation to discover a dead man in their daughter's bed. Thinking they're investigating the murder of a squatter, Castle and Beckett soon find themselves unraveling a multi-million dollar heist. Meanwhile, Castle tries to keep Beckett from finding out that they've been romantically linked when he's featured as one of New York's 10 most eligible bachelors.
The investigation into the shocking death of a museum curator, crushed by a falling gargoyle, takes a bizarre turn when Castle and Beckett learn that he isn't the first member of a recent archeological expedition to die. It turns out there was a legend inscribed over the burial chamber the team unearthed warning that "all who gaze upon the face of the mummy are doomed." Was the curator just the latest victim of "The Mummy's Curse"? And if so, what does that mean for Castle, who snuck a peek at the mummy when no one was looking?
Nothing is as it seems when Castle and Beckett investigate what appears to be the assassination of an intelligence operative. Meanwhile, Beckett's romance with Demming threatens her relationship with Castle, forcing them to confront their feelings for each other.
Beckett hasn't heard from Castle since he left for the Hamptons months ago to finish writing his second Nikki Heat novel, "Naked Heat." The most Beckett, Ryan and Esposito have seen of Castle is a bookstore standee of him advertising an upcoming book signing. So when Beckett and her team burst into a shadowy apartment on the trail of a murderer, the last thing they expect to see is the real-life Castle standing over a dead woman's body holding a gun. As Castle protests his innocence, Beckett has no choice but to arrest him on suspicion of murder.
When a famous psychic is murdered, Beckett and Castle search for her killer while also carrying on a spirited debate on the existence of extrasensory abilities. Evidence mounts on both sides, especially when a letter arrives from the victim, penned the day she was killed and predicting her own death -- or was it written by a clever killer, hoping to throw off the investigation?
When a coded document hidden by a murdered bail bondsman gets Castle's imagination running wild, Beckett must steer the case back to the violent felons who populated their victim's world - only to discover that maybe Castle's crazy theories aren't so crazy after all. Complicating matters is the surprise arrival of Beckett's ex-partner (now a bounty hunter). As the two reunite over a history that Castle has no part of, Castle is forced to watch the relationship take a turn towards the romantic.
Mysteries abound when pallbearers at a funeral lose control of a surprisingly heavy casket only to have a second unknown woman tumble out along with the original deceased. When Castle and Beckett learn that the victim was a doctor at County Hospital, their investigation takes them into the world of amorous, bed-hopping physicians. Did jealousy turn to murder, or did the doctor's mysterious work outside the hospital lead to her demise? Meanwhile, Castle's relationship with Gina is challenged when she tries to bond with Alexis.
When a beautiful woman is found dead in an alley, all clues point to her being a victim of the notorious Triple Killer. The Triple Killer, or 3XK, terrorized New York City four years ago, then mysteriously disappeared. Now he's back. In a deadly battle of wits, Castle and Beckett race against time to stop 3XK before he claims his next victims.
Responding to an "Officer Down" emergency call, Castle and Beckett's latest case takes a shocking turn when it's revealed that the victim isn't a cop but a male stripper dressed up as one. The murder leads them into the world of male strip clubs, the hardships of struggling actors, and the price that people pay in pursuit of fame. Did our victim's dreams of stardom get him killed, or was there something more nefarious afoot?
Astrophysicist Marie Subbarao (35)'s corpse is found, with all symptoms of fatal explosive decompression. Her ex Ted Carter, a colleague at the institute, has an alibi. An SF author friend also points to Castle's remark that everything seems to point to aliens. However the team's digging leads to FBI agent Westfield, whose agency goes to extraordinary lengths to stop their investigation, yet fails to keep from them Chinese Ung Kyu's involvement.