Ep 1. Highest Castle, Deepest Grave

Hawaii Five-0 season 4 episode 1, titled "Highest Castle, Deepest Grave", is a thrilling action-packed episode that sets the tone for the entire season. As the episode begins, we see the team back in Hawaii after their tumultuous trip to the mainland. However, their peaceful return is short-lived as they are called to investigate a murder at a historic castle.

The victim, a local historian, was discovered buried in the castle's moat, leading Five-0 to suspect foul play. The investigation takes them on a journey into Hawaii's past as they uncover secrets about the island's history and monarchy. Along the way, they encounter resistance from those who want to keep the past hidden and face danger from those willing to kill to protect their secrets.

One of the standout parts of this episode is the introduction of new character, Lieutenant Catherine Rollins, who eventually becomes a love interest for Steve McGarrett. Her appearance is a game-changer for the team, and her intelligence and skills quickly prove vital to the investigation. The episode also delves deeper into the personal lives of the characters, adding emotional depth and making them more relatable.

The storyline is full of twists and turns, as Five-0 races against time to find the killer before they strike again. The stakes are high, and the team's relationships are put to the test as they work to unravel the case. The beautiful setting of Hawaii only adds to the episode's appeal, with stunning scenery and iconic landmarks.

This episode also explores themes of power, corruption, and loyalty. It showcases how history can shape the present and how secrets can be dangerous. The characters' decisions have real consequences, and it's interesting to see how they navigate through moral ambiguity.

In terms of the acting, the cast delivers fantastic performances that heighten the tension and emotion of the story. Alex O'Loughlin and Scott Caan, in particular, have great chemistry and play off each other well. The episode also features Emmy Award-winning actor Margo Harshman, who portrays a key suspect in the investigation.

In conclusion, Hawaii Five-0 season 4 episode 1, "Highest Castle, Deepest Grave", is an exciting premiere that sets a high standard for the rest of the season. It combines action with emotional depth and explores relevant themes while showcasing the beauty of Hawaii. It’s a must-watch for fans of the show and newcomers alike.