Frank Mallory had been convinced that Doyle was going to shoot the child.
He'd seen the barrel of the Beretta aimed at her head, seen the expression on the counter terrorist's face. There had seemed only one possible outcome.
The thirty-two-year-old plain-clothes policeman had watched the entire tableau in muted shock, tempted fleetingly to draw the Smith and Wesson. 38 from the holster beneath his flannel shirt, but he had watched and waited.
Watched as Doyle had spoken into the phone.
Watched as he and the little girl had headed off towards the steps which would take them back down to the station's ticket office.
Now he watched from one end of the carriage as the tube train approached Chancery Lane station, glancing up from his copy of the Standard every now and then, ensuring that Doyle and the girl didn't slip off the train unnoticed.
Mallory had no idea where the counter terrorist was taking his small charge.
No idea what he was going to do to her.
How could he point a gun at her?
Mallory thought of his own child and, as he glanced at Doyle, felt a swift but overwhelming surge of hatred for the man.
The poor little sod must have been terrified.
And yet, as the plain-clothes man watched, Lisa was sitting close to Doyle.
Probably scared to move.
The carriage was relatively full so Mallory's job was made that little bit easier. When more passengers boarded at the station, most of the seats were taken.
People were moving about in the aisle, trying to find a seat or at least a hand-hold before the train lurched out of the station.
Mallory glanced across towards where Doyle had been sitting.
He couldn't see him.
The plain-clothes man tried to control the panic which struck him like a slap in the face.
What if Doyle and the girl had slipped off unnoticed?
How the hell was he going to find them now?
Mallory leaned forward slightly in his seat.
Still no sign of Doyle, but he could see the girl.
There was a young woman sitting next to her now, occasionally smiling up at Doyle, sometimes at Lisa.
Doyle stood in the aisle gripping the handrail, his other hand dug in his pocket.
Mallory breathed an almost audible sigh of relief and settled back to his newspaper, scanning the same words he'd already looked at a dozen times and still unable to remember one of them.
As the train passed through Holborn he saw that the counter terrorist and the little girl were still on board.
So too was the young woman Doyle had given up his seat for.
She had pulled a paperback from her handbag and was scanning it, pausing every now and then to point something out to Doyle who leaned close to her as she spoke.
From his position at the other end of the carriage, Mallory couldn't hear what they were saying. All he was aware of was the warmth of the young woman's smile.
Even Doyle managed a grin a couple of times.
Lisa's face never changed expression.
That look of bewilderment and concern remained etched upon her features.
Mallory glanced at Doyle once more.
What are you up to?
It was as the train approached Tottenham Court Road station that Mallory saw the counter terrorist extend a hand towards Lisa, both helping and beckoning.
She took the hand almost fearfully.
Doyle bent his head quickly and leaned close to the young woman with the dog-eared paperback.
She laughed out loud.
Doyle and Lisa moved towards the sliding doors of the carriage as the train pulled into the station. Mallory felt his heart beating a little faster.
Take it easy.
As the train stopped, the doors slid open and Doyle stepped out, Lisa's small hand held firmly in his.
Mallory waited a second or two then followed.