LL 5107 then QR 3573 at Barcelona
Prague → Barcelona → Cagliari
Timetable, Barcelona time
13:15LL 5107 from Prague at the gate
11:05QR 3573 to Cagliari leaves the gate
21 h 50 apart on the timetable, overnight
QR 3573 leaves 21 h 50 after LL 5107 arrives on the timetable: more than half a day, so not a connection we count.