Night train from Berlin to Brussels
There currently is one option to travel by night train from Berlin (Germany) to Brussels (Belgium), taking approximately 15 hours: Namely the NJ 424 operated by ÖBB.
The Austrian Federal Railways (ÖBB) operate the Nightjet and Euronight trains (the latter together with other national railway agencies). The ÖBB usually offer three types of carriages in their night trains: seats, couchettes, and sleepers. Seats are for the bravest, while couchettes and sleepers provide a more comfortable journey. Couchettes accommodate up to six people, while sleepers are private compartments for one to three people. They sometimes include a private bathroom or even a shower, sometimes only a sink.