Fitz struck Sophie as very cute at first, and the two now have a strong bond. For their Cognate training, they have to reveal all of their secrets, which makes their relationship even more intimate. They greatly trust each other and understand each other's minds completely. They are always there for moral support, often crying or laughing together. Sophie and Fitz have developed a bond so strong they are capable of transmitting thoughts to one another from great distances.
Fitz was the elf that found her and showed her the Lost Cities. He was there when Sophie had to drug her family and leave them permanently, so he knows the pain she went through that day. Sophie has thanked Fitz for everything that day, saying that he introduced her to a new life. Sophie and Fitz are on friendly terms (though Sophie seemed to have hoped for more, despite stating she clearly wasn't ready for a boyfriend). Sophie thought long and hard when she went out shopping for his present and was severely disappointed when Fitz did not get her anything special. She had gotten him something that was to thank him for her first day in the Elvin cities. It has been shown that Sophie has had a crush on Fitz since they first met. She thought he had beautiful eyes, and when she nearly lost hope, when she thought she was about to die, she thought of Fitz.
Fitz mourned her deeply and blamed himself, thinking that she'd died; however, he was one of the first people to find her after her escape. Fitz was overjoyed by Sophie's recovery after the light leaping incident, but he remained worried about her afterward.
Throughout Exile, Sophie and Fitz were able to telepathically transmit to each other because Sophie's impenetrable mind fractured. Fitz could get into Sophie's head, but his voice was very loud and gave her painful migraines. When Alden's mind broke, Fitz shut Sophie out, thinking she was to blame and that he should have been with his dad instead of her when Alden was injured. Despite this, Sophie thinks that he had every right to be mad at her because he may have lost his father forever. Right before she healed Alden, he took her outside and privately apologized to her. She immediately accepted.
In Everblaze, they grew closer together, and Mr. Forkle showed Fitz how to safely enter her mind. To do so, Fitz transmits a mystery phrase to make her subconscious trust him, and her subconscious lets him in. They also both entered a Telepathy class with Sir Tiergan during Everblaze. They practiced many trust exercises, which involve revealing secrets.
In Neverseen, when Sophie and Fitz joined the Black Swan (along with Dex, Keefe, and Biana), Mr. Forkle and Granite said that they were going to train Sophie and Fitz as Cognates. Fitz was excited about the idea, but Sophie was nervous about revealing her crush on him. During Cognate training one day, Sophie almost told Fitz that she likes him, but Keefe interrupted. Fitz continued to beg Sophie to reveal her secret to him throughout Neverseen and Lodestar.
In Lodestar, they grew closer. Fitz was more open with Sophie and began to show more affection for her. He gave her Cognate rings as a Midterms gift, which she thought she liked "a little too much." Sophie's crush on him continued to develop. Fitz may also have nearly kissed Sophie at one point, but Keefe interrupted before he could.
During Nightfall, Fitz often gave Sophie gifts, despite having no special occasion as an excuse. She promised that after they saved her parents, she would reveal the secret she was hiding. In Flashback, Sophie and Fitz became extremely close. Fitz told Sophie that wanted only her to be on his match list, causing Sophie to tell him about her own crush on him. They almost kissed immediately after this; however, it was interrupted by Silveny's transmissions. They eventually decided to hold things off until Sophie was ready to start "dating." It turned out he had liked her since when he was stabbed by the arthropluera in Neverseen. Sophie no longer denies it when people call her his girlfriend or her boyfriend.
The relationship between Sophie and Fitz is popular between Keeper of the Lost Cities fans due to the rivalry between Keefe Sencen and Fitz over Sophie.
- The ship name Sophitz is composed of the Soph of Sophie and the itz of Fitz; Sofitz is composed of the So of Sophie and the fitz of Fiztroy; Fitzphie is composed of the Fitz of Fitzroy and the phie of Sophie.