The Best Episodes Written By David Grae

After President Dalton hears about a sonic attack at the U.S. Embassy in Bulgaria, he thinks Russia is to blame and uncharacteristically threatens them with military force, leaving his cabinet concerned about his mental status.

Castle and Beckett uncover that a bullet is missing from the crime scene while investigating what happened when an art dealer was gunned down in his own gallery. However, when it turns out there was a witness to the murder, they need to refresh the man's memory, only to find out that he suffers from amnesia and can't even remember who he is.

Castle and Beckett look into the murder of a young mathematician gunned down with a 200-year-old bullet, sparking some wild theories by Castle about a time-traveling killer. When their investigation uncovers a tricked-out DeLorean and a suspect in Victorian clothing, is it possible Castle's crazy idea has some validity? This winding tale twists through the towers of Wall Street and into the world of a secret steampunk society that embraces the romance and simplicity of the past, while coupling it with the hope and promise of the future.

While Elizabeth is in Libya to help negotiate an end to their civil war, a tragic accident with her chauffeured car embroils her in an urgent situation to secure medical care for a gravely wounded local girl.

Elizabeth and cabinet members brace for the fallout at home and abroad as President Dalton prepares for a retaliatory nuclear attack on a country that has reportedly just launched missiles bound for the U.S.

Elizabeth goes head to head with a U.S. governor over the state's new policy of separating unauthorized immigrants from their children. Also, she and Henry plan to renew their wedding vows.

Elizabeth must fend off a baseless investigation into her past that threatens to derail the first major legislation of her presidency. Also, First Gentleman Henry squirms after his appearance on The Late Show with Stephen Colbert results in heightened scrutiny of the romance in the First Couple’s marriage.

When two separate murders are committed on the same night, Castle wagers Ryan and Esposito that he and Beckett will solve theirs first. The frenzied race to catch their respective killers and win the bet leads each investigative duo to a likely suspect, only to find that they both have airtight alibis. But bizarre twists in both cases force the two teams to work together to unravel the mind-bending mystery behind each murder.

When Castle's novel ''Heat Wave'' becomes a movie, actress Natalie Rhodes accepts Beckett's invitation to visit and learn about the character she will play; Natalie observes Castle and Beckett's investigation of the murder of a matchmaker.

A murder scene complete with lots of blood but no victim and high tech life-extension science are all part of the investigation as Castle and Beckett try to solve a murder without a body. Meanwhile, Alexis waits to hear news about her application to Stanford

When Castle appears on a late-night talk show to promote his book, Heat Wave, legendary host Bobby Mann leans in during a commercial break and whispers, "They want me dead." When Mann dies later that night, seemingly of natural causes, Castle has to convince Beckett that there was foul play. During the investigation, Castle is seduced by a Hollywood hottie, who was the other guest on Bobby Mann's show the night he died.

Castle and Beckett investigate the murder of a Wall Street trader, but the case takes a shocking turn when the they discover the victim was an undercover informant for the U.S. Attorney’s office. To complicate matters further, the U.S. attorney involved is Elizabeth Weston, Captain Gates’ estranged sister.

Castle and Beckett’s plans for a romantic weekend in the Hamptons are interrupted when a dying man stumbles into Castle’s backyard, collapsing into his pool. Unable to escape the lure of the investigation they join up with the small town’s well-intentioned, but inexperienced sheriff to find the killer,

Elizabeth is confronted by a hostile reporter who threatens to publish confidential documents that were leaked from inside the State Department. Later, Henry is dragged into an international negotiation when his wife uses his job as leverage to broker a deal with Pakistan.

When a teenaged boy whose family has recently fallen on hard times is found dead in a boat in Central Park, Castle and Beckett must piece together the mystery behind the boy's final moments. Meanwhile, Castle mulls over leaving Martha home while he chaperones Alexis' trip to Washington, D.C.

When a lothario is killed, Castle and Beckett suspect that the victim’s mysterious double life holds the key to his murder. Their investigation leads to a shocking twist that threatens to disrupt Ryan’s wedding with Jenny

Elizabeth secretly travels to Iran in an attempt to prevent a coup that could impact President Dalton’s administration. Also, she brings her staff up to speed on the investigation into Marsh’s death.

As Elizabeth prepares for the arrival of Iranian President Shiraz to sign a nuclear treaty, she uncovers a top secret plot to assassinate him on United States soil. At the same time, she must deal with a massive protest by the Human Rights Campaign in response to Iran’s plans to stone a gay citizen to death. Also, Elizabeth sees a therapist to deal with her PTSD.

After they uncover a secret that could ruin Maria Ostrov’s reputation, Elizabeth and President Dalton head to Switzerland to meet with her and use the information as leverage to find a peaceful solution to the escalated conflict with Russia. Also, Dmitri requests to be released from his duties as a spy.

Continuing from the season premiere episode, Beckett races against time to find a stolen toxin capable of killing tens of thousands of people. To make matters worse, Castle was exposed, leaving him with less than 24 hours to live.

Elizabeth, Henry, and Isabelle investigate a plane crash that killed former Secretary of State Vincent Marsh. Nadine reenters the dating scene after she agrees to go on a date with a NASA scientist.

Castle & Beckett get an up-close-and-personal view of a "Real Housewives"-esque reality TV series, "The Wives of Wall Street," when they investigate the murder of the show's rising young star. Meanwhile, Castle's attempt to give Beckett a Valentine's Day gift goes horribly wrong.

The United States debates enacting a “render safe” mission to secure nuclear weapons that belong to the Pakistani government before it collapses, while the Murphy Station pursues the terrorist Jibral Disah.

With Algeria on the brink of a civil war, Elizabeth delicately negotiates a regime change, but her plans go awry when Roy Curtis, the trusted U.S. Ambassador to Algeria, dies unexpectedly. Also, Henry fights to save religious antiquities in Algeria when he discovers they are being destroyed by Hizb al-Shahid.

Elizabeth goes head to head with a U.S. governor over the state’s new policy of separating unauthorized immigrants from their children.