W4 6018 then FR 7815 at Fiumicino
Barcelona → Rome → Thessaloniki
Timetable, Rome time
11:55W4 6018 from Barcelona at the gate
06:10FR 7815 to Thessaloniki leaves the gate
18 h 15 apart on the timetable, overnight
FR 7815 leaves 18 h 15 after W4 6018 arrives on the timetable: more than half a day, so not a connection we count.