Finding Episodes in event sequence In the paper "Discovery of frequent episodes in event sequences" by Mannila et al., a method for finding frequent episodes in an event sequence if a class of episodes and a sequence of events is given. 

It is not clear to me how to find episodes in the first place. I would like to know if there are any tools, algorithms, or published work that can be used to this end, or which describes a method to find episodes in a given stream.
The paper that you cited references two other papers that explain the method you are looking for here and here.  The second one is behind a pay wall.

But... these look like deterministic methods to me, and I suggest you use a machine learning method instead.  You basically need to separate events from each other using some sort of clustering algorithm.  I suggest you use DBSCAN and adjust the parameters based on whether you want every event to be assigned to an episode or not.

Another algorithm that might work well is simple k-means clustering with the addition of an elbow method or silhouette score to determine the optimal number of clusters.