Complex sentence: Rose later finds out that Dimitri's body wasn't found when another team of guardians went back into the caves the next day, confirming that Dimitri was not killed, but was made Strigoi.
Split into simpler sentences: Rose later finds out that Dimitri's body wasn't found. Another team of guardians returns to the caves the next day, confirming that Dimitri was not killed, but was made Strigoi.