Who does jonathan think he sees in the thick fog? the fighting ground

The fighting ground:

When Jonathan was running in the fog, there was thick fog surrounding him and he could hardly see anything through the fog and while running he thought that one of the pursuers was following him so he started running even faster to save himself.

But suddenly he heard a voice calling out his name and it was a very similar voice. While running he realised that it was his sister who was calling out his name as johnny and listening to this he took a sigh of relief and stopped running so fast.