you will be leaving on the following train:

09:45am         Depart Montreux with Golden Pass train #3118
11:32pm         Arrive in Zweisimmen

You have to take this train. If you miss it you will loose your seat reservation.

You are in wagon #30 and have seats #61 and 62. according to separate vouchers (please print out these seat reservations and bring them with you).

Lunch
This is a direct train until Zweisimmen. You could interrupt the journey in Zweisimmen and have lunch at one of the restaurants around the station. Or you could bring sandwiches again and continue to Interlaken right away!

Zweisimmen to Interlaken [West/Ost]
From Zweisimmen you have direct trains to Interlaken [West/Ost] at 13:38pm and 15:38pm. And other trains which require a change of trains in Spiez are leaving Zweisimmen at 14:01, 15:03 and 16:00. You will not need a seat reservation and can take any train you like.

Option Lake Cruise
If you have good weather and you would like to take a lake cruiser, you could get off the train in Spiez. From the Spiez train station, it is about a 10 minutes "sign-posted" walk down to the landing, from where you could take a boat to Interlaken West. There are also a few restaurants right at the landing, if you did not have lunch yet or would like to sit down for coffee. (You could use fast baggage today if you plan on the Lake Cruise so you don't have to carry all your luggage with you).