Good detectives can take the observable facts of a case and draw conclusions or make inferences based on those facts. This is not about "guess work"; it is about using evidence from the scene to find out what is must be true that is not in the scene.
For example, if I find an empty egg shell in a nest, I can conclude that a baby bird hatched from the egg. This is based in the fact that the shell is in a bird's nest. Of course, my inference may be wrong. In fact, another animal may have robbed the nest and eaten what was in the egg, leaving the empty shell behind.
What I could not infer is that a zombie and a wizard were fighting over the egg, when suddenly an alien hatched from the egg and defeated them both. That's a creative guess, but it's not an inference at all.
Below, you are presented with a choice between three strange pictures. You may choose only one and click it to make it bigger. Make your observations just as in the previous modules, based on what you see. Note every possible detail.
Once you have the "facts", you may draw a conclusion about what happened just before this picture was "taken". In other words, if this picture was the result, what happened to cause it?
Finally, now that you have inferred what happened, how do you predict the situation will be resolved in the scene that follows?