The episode began with Castle and Beckett announcing their marriage to their friends, who were not too happy about not being included in the ceremony. However, the tension was cut short by a phone call informing Beckett that a murder had occurred. On the way to the station the couple discussed their honeymoon, where Beckett confessed that she had used all her vacation days searching for Castle when he was missing in the pilot. There would be no honeymoon.

However, thanks to the new case they would be going a trip of sorts. After discovering that the dead woman, Whitney Williams (Sarah Butler), was likely poisoned at a dude ranch in Arizona and the sheriff there would not cooperate, Castle hatches a plan to go undercover as honeymooners (“it’s the only way”).

At the dude ranch, the newlyweds sported Old West outfits as the man in charge, James Grady (Keith Szarabajka) showed them around.

After talking their way into Whitney’s old room they met a man, Tobias (Tyler Hilton), staying in the adjacent room, who reveals that Whitney had been seeing a married ranch hand while staying on the ranch.

They begin searching the resort for all the ranch hands to see which were married by seeing if they had rings.

In the saloon, Castle found a married ranch hand while laying cards. Playing in Old West character, Rick accuses the ranch hand of cheating, but things got real when the man forcefully threw Castle out of the saloon, wondering what he knew. After questioning him, Castle found out that Whitney was actually just trying to get his key to get dynamite from the ranch shed.

On horseback, Rick and Beckett went to visit a reservation that they found out Whitney had visited.

However, when they got there, it turned out that all she wanted from the place was to know from one of the Native Americans the meaning of a word for streams and rivers.

On the way back, the couple stopped to get intimate around a campfire and enjoy their real honeymoon. Unfortunately their horses got scared away when a rattlesnake came between them, and they were forced to walk through the night to get back to the ranch.

Rick got a call from the station where Whitney’s luggage had been found, including a letter claiming Whitney was close to uncovering a secret by the ranch.  The letter also mentioned two outlaws on a poster that Rick had been handed in the saloon, seemingly as part of the resort’s games. However, after asking a bartender in the saloon, they found out that the outlaws stashed a fortune of gold and Whitney had been searching for the treasure.

Rick and Beckett use one of Whitney’s maps and tracked down the gold where they found the body of Whitney’s father. Someone had killed her father while searching for the girl and the same killer had murdered Whitney.

Back at the station, Esposito (Jon Huertas) questioned a former partner of Whitney’s father, who revealed the name of the killer – James Grady. While Beckett was off showing the sheriff the body of Whitney’s father, Grady and Rick got into a Wild West style showdown.

Luckily, Beckett showed up at the last second to save Rick and arrest Grady.