EW 520 then BT 684 at Barcelona
Cologne → Barcelona → Riga
Timetable, Barcelona time
14:45EW 520 from Cologne at the gate
14:05BT 684 to Riga leaves the gatealso IB 7848
23 h 20 apart on the timetable, overnight
BT 684 leaves 23 h 20 after EW 520 arrives on the timetable: more than half a day, so not a connection we count.