Izzy was born in the Last City, in the shadow of the Traveler. His parents divorced when he was still very young, and Izzy was subsequently raised by his anxious, doting mother. Even as a child, he had an adventurous streak that led to several near-death scenarios; most notably when Izzy and his friend, a young Suraya Hawthorne, ran into a group of Fallen whilst illegally exploring beyond the City walls, and had to be rescued by a passing team of Guardians. However, Izzy was also a caring and compassionate boy who was deeply aggrieved by Suraya's decision to self-exile from the City. He eventually drifted into a career in medicine, and for a time the risk to his medical career encouraged him to stay within the walls. As an adult, he resumed his association with Hawthorne and the rest of the "City rebels". Izzy proved a capable scout, and skilled field medic. Whilst more accepting of City politics than some of his seditious friends, it was clear that Izzy was happier and more fulfilled living outside the City.
When the Red Legion attacked the City, Izzy helped to coordinate the tide of refugees flooding out into the EDZ. It was during this time that he met Nyx-13 and the other Guardians, treating many of the Lightless survivors who had fled the city alongside their mortal charges. Izzy had long been fascinated with the Traveler's Chosen - something Suraya scornfully referred to as Ezekiel's little hero-worship - and was particularly enthusiastic about working alongside them. Little did he know, he'd soon get his wish. When Maledict and his fireteam finally converged in the EDZ, they found themselves in need of a doctor to help rescue one of their own from behind enemy lines. Izzy subsequently accompanied Maya on an audacious mission to recover Gideon from the Cabal prison fleet. His courage soon became the talk of the City, impressing both human and Guardian alike. Izzy later leveraged this to earn himself a place on Mal's fireteam - the only human in City history to do so.
In the wake of the Red War, Izzy returned to the City in order to care for a still-recovering Gideon. Now the talk of the town, as far as his actions during the Red War go, Izzy has been enjoying new-found attention from some of the City's notable Guardians - including Lord Shaxx, and legendary sparrow-racing team Enoch Bast and Marcus Ren. Izzy and Gideon briefly left the City in order to investigate a Vex plot on Mercury, marking Izzy's first foray into the Infinite Forest. More recently, Izzy seems to have caught the interest of the infamous "Man With the Golden Gun", Shin Malphur; the two met briefly on the clifftops outside of the EDZ, where Shin vaguely hinted at having been impressed by Izzy's "purity of intent".