EC 7154 then QR 3518 at Barcelona
Milan → Barcelona → Bilbao
Timetable, Barcelona time
16:10EC 7154 from Milan at the gate
13:25QR 3518 to Bilbao leaves the gate
21 h 15 apart on the timetable, overnight
QR 3518 leaves 21 h 15 after EC 7154 arrives on the timetable: more than half a day, so not a connection we count.