|Swati Das's parents break down. Pictures by Sanat Sinha
Two Jadavpur University students have been rescued and the bodies of two others have been recovered. One student remains un-traced. An air of confusion and apparent contradictions, however, envelop the tragedy with different versions of what happened emerging at every turn.
Here are some of the 'mysteries' that police are trying to grapple with:
Bappaditya Chatterjee said that around five in the evening on Friday, when he finally emerged from the waters of the Sobha, he was surprised to find his cellphone still functioning.
Police wonder how his phone could be working after the thorough soaking.
Even assuming that it was miraculously working, why is it that he took a full two hours to call up a friend in Calcutta'
Manindra Gope, a district CPM leader who had been part of the rescue team, said: 'I asked Bappaditya why he took two hours to inform Calcutta about the accident. What was he doing in these two hours' I got no reply.'
If the five students were going trekking and were members of the university's trekking club, why did they not take the university's permission and follow procedures like filling up a form before leaving for Purulia'
Why did Subhankar Saha tell his family that he was going for a holiday in Digha when in fact he was headed for Purulia' What was the reason for concealing a simple thing like a trekking trip from his family'
Swati Das's body was found minus clothes in the Ayodhya forest. How could that have happened, especially as she was seen by the villagers of Egra, dripping wet but fully clothed, in tracksuit bottoms and a T-shirt, after she had emerged from the waters of the Sobha'
If they were going on a trekking expedition, why was it that other than a tarpaulin sheet, which they had used to set up a tent, no other equipment was found in their possession'
Why were they so far off the usual route'
Local forest beat officer Partha Mahato said they were about 15 km off the trekking route when they decided to cross the river. So, where were they headed'
Why did Swati and Arundhati suddenly decide to flee into the forests all by themselves, as claimed by Kaushik' What were they so afraid of'
Why had the five decided to go on a trekking expedition during monsoon'
It is well known that during this season some of the stretches in the Ayodhya area can be very tricky and unsafe and the rivers swollen.
How is it that Bappaditya has given two different versions of how they attempted to cross the river'
In one, he has said they used a rope to cross it; in another he said they attempted to cross it jumping from one boulder to another.
'If we get answers to even half of these questions, we would be able to provide a decent account of what really happened and how,' said Banibrata Basu, the western range inspector- general of police.