  This paper presents the second version of the dialogue system named Alquist
competing in Amazon Alexa Prize 2018. We introduce a system leveraging
ontology-based topic structure called topic nodes. Each of the nodes consists
of several sub-dialogues, and each sub-dialogue has its own LSTM-based model
for dialogue management. The sub-dialogues can be triggered according to the
topic hierarchy or a user intent which allows the bot to create a unique
experience during each session.
