Eisenhower Holt is the Tomas father of Hamilton, Reagan, and Madison Holt.
Eisenhower Holt went to West Point and knew fellow student Arthur Trent who laughed at his answers in class before Eisenhower was kicked out. Eisenhower married Mary-Todd Holt, and together they had three children, Hamilton, Reagan, and Madison. Eisenhower knew Hope Cahill as she was also a Cahill, and Arthur's wife though they later died in a fire that burned down the house. They were frequent visitors at the week-long winter holiday at Grace Cahill's estate. Two weeks before Grace died the Holts went to Monument Valley on Cahill work, Eisenhower posting a blog about it. They also visited the world's largest ball of twine.
After Grace died, Eisenhower and the Holts went to her funeral, Eisenhower putting a shovel of dirt on her grave. The Holts went to the will reading, and William McIntyre played a video of Grace saying they could each take a million, or hunt for the 39 Clues. The Holts chose to hunt, and got the clue sheet saying: RESOLUTION. Fine print. Seek out Richard S____. Eisenhower tried to find out how much each word was worth,and Alistair Oh helped, saying that for them it was around 500,000. The Holts then formed up, and left, but came back around, following Amy and Dan Cahill into the library, behind Alistair. Eisenhower made the girls jog, and after a while Hamilton tried to smoke them out, but got careless with the lighter fluid and burnt the house down.
Later, they tracked the Cahills two the Franklin Hall, and set up a concussive grenade to get Amy and Dan when they left the arch, but it got the, wrong team. Annoyed, the Holts went to Pairs, and were able to ambush Alistair, stealing the Poor Richard's Almanack from him, reading a note written by Hope about the Maze of Bones, but Irina Spasky stole the book from them. The Holts got a rental car, and drove it in Siene. They stole an ice cream van, and implanted surveillance taps inside a Lucian stronghold to get it back. Before they could do their assault, Amy and Dan slipped in the stronghold. They listened to them, and assumed they got the Almanack from Irina. Eisenhower called the family to order, saying that this was a bad idea and they wouldn't fail to capture Amy and Dan this time, and then took the van through the streets of Pairs, going to the isle they heard Amy and Dan mention.
At the Île Saint-Louis in France, the Holts went to 23 Rue de Jardins, a grave site, and saw Amy and Dan fall in a grave marked with their names. The Holts moved in, thinking they were at the Maze of Bones, Hamilton revealing that they set the museum bomb and burnt Grace's mansion down. Eisenhower told the kids that they must have the Almanack and a cement truck pulled up with thugs and shovels. Eisenhower thought it was a planned ambush, and decide to leave Amy and Dan, Dan trying to convince Reagan to save them. Dan lied Amy knew the Clue, and would tell them if they were pulled out. Eisenhower pulled them out, and the Holts went to fight the thugs, Eisenhower grabbing one's shovel, and swinging the person into the cement truck. The Holts were then hit with a misfire of Dan's concussive grenade, and knocked out on the isle.
Now with a score to settle with Amy and Dan, the Holts took the ice cream truck to the St. Pierre de Montmarte church, seeing Alistair and Irina Spasky ambush the Cahills and Nellie Gomez. Eisenhower threw frozen ice cream all of them, hitting Aistair and Irina. The whole family grabbed ice cream, and Amy and Dan ran inside St. Pierre. The Holts followed up the bell tower to the trapdoor leading into the belfry, but when Eisenhowr slammed on it, a bell was on the trap door. When Eisenhower broke through he saw Amy and Dan alone, Amy pointing to Ian Kabra escaping with the vial below. Eisenhower was going to crush them when Reagan called the police were coming, causing the Holts to flee.
The Holts later realized that Amy and Dan had the Clue, and got hamburgers in Dijon, France waiting for the kid's train to stop. The Holts snuck by the porters, and began pushing forward, and Eisenhower made a lady drop her parakeet. While he waited, he saw Amy and Dan run, and burst through where Nellie sat on his back. Hamilton put her in her seat, and the continued, reaching a mail cart with mail bags piled in front of the door. Eisenhower smashed it open, knocking Dan to the floor while Amy beaned him with a hockey stick. The rest of the Holts entered, Mary-Todd helping Eisenhower. When the kids lied about the Clue, Eisenhower began to strangle Dan, but Amy showed him where the KV 617 music sheet was in the overhead. In the overhead, Saladin had shredded the sheet, and Eisenhower grabbed the cat, who promptly coughed a hairball covered in musical notes. When the conductor asked the Holts if they have tickets, they jumped out the train, rolling on the hill in formation.
Eisenhower was able to hack into Saladin's tracking device, finding it on...Alistair Oh. Tailing after Alistair from Venice to Japan the Holts hacked wirelessly into their computer at the Tokyo library scrolling through Toyotomi Hideyoshi databanks.