After the war with the Covenant, ODST Edward Buck was contacted by Jun-A266, former Spartan-III Noble Team member and current Spartan-IV recruiter. Buck initially refused, insisting that his entire squad of ODSTs, Alpha-Nine, would have to be part of the Spartan-IV program for Buck to consider joining. Eventually the Spartan-IV program got enough funding to recruit all of Alpha-Nine, and Buck joined, along with Mickey and Romeo.
The team trained as part of the second class of Spartan-IVs, and became embroiled in a terrorist plot to destroy the Spartan-IV training station. The plot failed, however, and Alpha-Nine completed their Spartan-IV training. A year later, during Operation: COALPEPPER, another terrorist plot unfolded, this time involving Mickey, who had been turned by the United Rebel Front against the UNSC. The plot nearly worked, but Buck and Romeo managed to defeat the URF and subdue Mickey.