FR 4500 then FR 1986 at Dublin
Cologne → Dublin → Nantes
Timetable, Dublin time
11:00FR 4500 from Cologne at the gate
05:45FR 1986 to Nantes leaves the gate
18 h 45 apart on the timetable, overnight
FR 1986 leaves 18 h 45 after FR 4500 arrives on the timetable: more than half a day, so not a connection we count.