‘I haven’t a clue what you’re talking about,’ said Strachan.
‘It’s simple. Scholar’s Mate. One of the easiest and quickest ways to mate in chess.’
‘I don’t understand.’
Elina pointed to the map. The number of squares gave it away. You see, if you take Soochow Creek as the baseline and move the pieces found at each of the murders, they correspond to the moves in Scholar’s Mate.’
Strachan stared at the map, a frown appearing between his eyebrows.
Elina grabbed the white chess pieces and lined them up along Soochow Creek. ‘Look, the first move is the pawn advance two squares.’ She slid the pawn forward until it rested next to the Shanghai Country Club. Then she advanced the queen to the War Memorial. ‘The queen comes out diagonally, and the other bishop pins the defending pawn.’ She moved the bishop to the square on the map where they had found the ice store. ‘To finish the check, the queen advances for checkmate.’ She banged the queens down right on the square with the Canidrome, and next to it the Cercle Sportif. ‘He even repeated the checkmate after you rescued Miss Cavendish. It’s very clever… too clever.’
‘But it doesn’t tell us where your father is now.’
Elina pulled her lips into a pout with her index finger and thumb. ‘No, it doesn’t… unless…’
‘What?’
She picked up the white king from its place on the map next to Soochow Creek. ‘Unless, this is the killer.’
‘The one who wins the game?’
Elina nodded.
Strachan stared hard at the map. Where was Danilov? He tried to relax, to remember everything the inspector had said to him. He closed his eyes and the words came back to him. ‘Back to where the game began, Strachan.’
He opened them and looked at the map. It had to be there. It was the only place. So obvious, he should have realised it long ago.
He looked around for his hat and coat, grabbing them from their place behind the door. He slung them over his shoulder and rushed out.
‘David, where are you going?’ Elina shouted after him.
A head appeared, framed in the door. ‘Call Chief Inspector Rock; we need the Rapid Action Force at the Sinza Water Tower.’
She jumped forward. ‘I’m coming with you.’
‘No,’ he shouted, ‘we need help.’
She kept coming, stepping out of the door.
‘Elina, you need to call him. Otherwise, your father will die.’
‘I want to come…’
‘You can’t, you need to leave this to me…’
She stepped forward again, only to find his arm coming down in front of her. ‘It’s my mother and father…’
‘And to save them, we need help. Make the call, Elina.’ With that last shout, he leapt down the stairs, leaving her standing in the doorway.
She hesitated for a moment, her mind a jumble of fear and duty and ideas. What to do? Follow David? Ring for help? Must save my father. Must save him.
She rushed back into the apartment and picked up the telephone, dialling the number as quickly as she could. Get help first and then follow David.
She knew exactly where he was going: the Sinza Water Tower.