Sam Leonard: "We've just done some freaky time travel thing; that's what anomalies are! Who are you people?!"
Matt Anderson: "We're the people who deal with this sort of thing, and we're gonna need your help."
―Sam learns the truth about the anomalies.[src]

Midshipman Sam Leonard is the sonar officer of the nuclear submarine, HMS Gartside. He is the only surviving crew member (besides the captain) who was present during a Jurassic creature incursion.


The HMS Gartside was cruising in the North Sea, when a strange signal was picked up on the sonar display. Midshipman Leonard reported this to Captain Marcus Yates, who asked for Leonard to look into it further. Sam listened to the outside ocean, and realised that there was some sort of animal outside. Realising that the animal was headed straight for the submarine, he informed the captain, who ordered the submarine to surface.


Abby and Sam examine the Theropod.

Abby Maitland, Connor Temple and Matt Anderson went on location to board the HMS Gartside, which would take them to the anomaly site. They met the Captain, who introduced the Officers and Midshipman Leonard. Sam was tasked with showing Abby the creature, which was washed up on the bow when the submarine surfaced. He asked Abby what it was, to which she responded, saying it was some sort of Theropod. At this point, he realised that it was a dinosaur, but he assumed it was deceased. However, Abby figured out that the Theropod was alive, just in a state of shock. Abby and Sam put the unconscious creature in the freezer to keep it in shock. Sam told the ARC Team that it would be a while before they reached the anomaly site, so they should get some rest. As they neared the anomaly site, the Captain ordered Officer Neal to make some coffee, since he had run dry. Upon reaching the anomaly site, Sam once again picked up a strange signal along with more electrical interference. The Captain ordered Midshipman Leonard to release the sonar array, to broadcast their position to the ARC. When he did, a Liopleurodon attacked it, and wrapped it around the submarine's propeller, disabling the sub along with its electrical systems.


Sam becomes the ranking officer, after the Captain is disabled.

The Captain was knocked unconscious, and Sam immediately went to Abby, Connor, and Matt, who were resting in some of the submarine's bunks. He informed them that they had lost power along with the Captain, and that they were close to the anomaly site. At this point, the lock on the freezer had failed, and Officer Neal had been attacked by the Theropod. Matt asked Officer Shaw to search for Officer Neal, leaving Sam as the only crew member in the control room. Upon entering the anomaly, Sam found that their depth had changed from 160 feet to 120, and Connor realised that the sea that they were in was probably in the Jurassic Era. It was at this point that Sam finally understood what anomalies were. Sam found a diagram of the submarine's electrical systems, and gave it to Connor, so that he could reset the fuse boxes. He also volunteered to man the Bathyscaphe to help free the propeller, but Abby and Matt went instead, as Sam was the only man who could restart the submarine when Connor was finished. He stayed onboard, locked in the control room while the two went in the Bathyscaphe, and Connor was following the wiring.


"Torpedo away!" Sam fires Connor's torpedo.

Midshipman Leonard let Abby and Matt back into the control room after they finished cutting the cables. He then let Abby out to look after Connor, after Matt armed her with a large wrench. After Connor managed to reset all four fuse boxes, he and Abby rejoined Matt and Sam in the control room. As Connor and Abby piloted the submarine back through the anomaly, Sam flooded the torpedo bay, with the Swimming Theropod inside. With the torpedo bay fully flooded, Sam allowed Matt to vent the room, sucking the Theropod out. This distracted the pod of Liopleurodon, which were violently attacking the submarine, and allowed them to escape through the anomaly. Once through, Sam got a torpedo warning, and notified the others. He braced for impact, but when none came, recovered quickly. He then fired Connor's torpedo, and closed the anomaly.