If you love food, get it beforehand
There’s no restaurant car in train. The only food is distributed by TCDD staff, a bottle of water, some fruit juice and biscuit (most probably only for sleepers). Buy what you need before you depart from Sirkeci, since there’s nothing in Halkali yet, and Kapikule is not different in midnight.
Passport check at Kapikule
Unfortunately, border police is not coming to you in Turkey, you have to go to him. In the middle of sleep, at about 14:30, someone (the staff) knocks the door and tells you to go to queue with your passport. After everybody comes, the officer comes, opens the pc. If you are lucky, it opens within 10 minutes. So all passengers wait at queue without doing nothing for 20 minutes, since officer doesn’t come 20 min earlier. Don’t bother, and use that time to get socialized with other passengers.
Passport check at Svilengrad
Thanks to border police of Bulgaria, they visit every compartment, get the passports, checks if it’s really you or not, and go. You don’t even have to get off the bed. The passports come back in half an hour. You can continue sleeping until then.
Stop at Dimitrovgrad for Bucharest train
In about half an hour after passport check by Bulgarian border police, if you are not in a deep sleep, you’ll recognize that train stops. There is Dimitrovgrad station. Bucharest wagons will leave the train there, and will follow another route towards Bucharest. It takes about 20 minutes. If you cannot sleep, it’s a good time to have some chat.
Everybody asks if the vibration in train bothers or not. Train has almost no vibration, no sudden breakes, fast turns etc. Put your phone on the table, and you’ll find it at exactly same place in the morning.
It’s not noisy, that’s sound of silence
Honestly, there’s a continuous sound of steel wheel touching steel rail. Regular clinks of rail weldings is also added in Bulgaria. For me they are like songs for sleep, but if you don’t like them, close the small window of your compartment. You’ll hear almost nothing very soon.
Photographing is a hard job
The train photography, as you may see some examples in Rail Turkey, is surely exciting. However, keep in mind that, almost whole travel is during night, doors of most of the comparments are close and it’s not easy to take a photo outside of small window even with cell phones.
Arrival at Sofia
You’ll arrive at Sofia in the morning. Sofia station is quite big, and there are enough facilities for basic needs. Station has metro and tram connection to city center. City center is 3 km away. It’s the second stop if you take metro. City is flat, sidewalks are wide, cars are respectful to pedestrians. It’d be good to have some walk after 10 hours of train travel.