In "The Tiger in the Tunnel," why was Baldeo uneasy?

One reason why Baldeo is uneasy is because of what he might encounter in the jungle.
Baldeo sets out for the railway station late at night. As he walks through the jungle, the forest creatures are the only things that can be heard. Accordingly, the thoughts of the creatures he might have to confront triggers his uneasiness:

The eeriness of the place was increased by the neighbouring hills which overhung the main line threateningly. On entering the cutting with its sheer rock walls towering high above the rails, Baldeo could not help thinking about the wild animals he might encounter.

Baldeo is uneasy because he does not know what is out there in the vast darkness.  He walks to his night job alone, and there is no one else around to dispel his uncertain thoughts.  These ideas drift to what might be waiting for him in the dark jungle.  Baldeo's uneasiness is further amplified when he thinks about "the man-eating tiger" that roams in the jungle.  Baldeo does not know what is out there, but he knows that what is there will not friendly to him.  He knows that "there is no shelter" when he is amongst the natural elements.  This lack of certainty causes Baldeo's uneasiness.