Nella turned aside instantly, hiding her face, and Miss Spencer, carrying a small bag, hurried with assured footsteps to the Custom House. It seemed as if she knew the port of Ostend fairly well. The moon shone like day, and Nella had full opportunity to observe her quarry. She could see now quite plainly that the Baroness Zerlinski had been only Miss Spencer in disguise. There was the same gait, the same movement of the head and of the hips; the white hair was easily to be accounted for by a wig, and the wrinkles by a paint brush and some grease paints. Miss Spencer, whose hair was now its old accustomed yellow, got through the Custom House without difficulty, and Nella saw her call a closed carriage and say something to the driver. The vehicle drove off. Nella jumped into the next carriage - an open one - that came up.
'Follow that carriage,' she said succinctly to the driver in French.
'Bien, madame!' The driver whipped up his horse, and the animal shot forward with a terrific clatter over the cobbles. It appeared that this driver was quite accustomed to following other carriages.
'Now I am fairly in for it!' said Nella to herself. She laughed unsteadily, but her heart was beating with an extraordinary thump.
For some time the pursued vehicle kept well in front. It crossed the town nearly from end to end, and plunged into a maze of small streets far on the south side of the Kursaal. Then gradually Nella's equipage began to overtake it. The first carriage stopped with a jerk before a tall dark house, and Miss Spencer emerged. Nella called to her driver to stop, but he, determined to be in at the death, was engaged in whipping his horse, and he completely ignored her commands. He drew up triumphantly at the tall dark house just at the moment when Miss Spencer disappeared into it.
The other carriage drove away. Nella, uncertain what to do, stepped down from her carriage and gave the driver some money.
At the same moment a man reopened the door of the house, which had closed on Miss Spencer.
'I want to see Miss Spencer,' said Nella impulsively. She couldn't think of anything else to say.
'Miss Spencer? 'Yes; she's just arrived.'
'It's O.K., I suppose,' said the man.
'I guess so,' said Nella, and she walked past him into the house.
She was astonished at her own audacity.
Miss Spencer was just going into a room off the narrow hall. Nella followed her into the apartment, which was shabbily furnished in the Belgian lodging-house style.
'Well, Miss Spencer,' she greeted the former Baroness Zerlinski, 'Iguess you didn't expect to see me. You left our hotel very suddenly this afternoon, and you left it very suddenly a few days ago; and so I've just called to make a few inquiries.'
To do the lady justice, Miss Spencer bore the surprising ordeal very well.
She did not flinch; she betrayed no emotion. The sole sign of perturbation was in her hurried breathing.
'You have ceased to be the Baroness Zerlinski,' Nella continued.
'May I sit down?'
'Certainly, sit down,' said Miss Spencer, copying the girl's tone.
'You are a fairly smart young woman, that I will say. What do you want? Weren't my books all straight?'
'Your books were all straight. I haven't come about your books. Ihave come about the murder of Reginald Dimmock, the disappearance of his corpse, and the disappearance of Prince Eugen of Posen. I thought you might be able to help me in some investigations which I am ******.'
Miss Spencer's eyes gleamed, and she stood up and moved swiftly to the mantelpiece.
'You may be a Yankee, but you're a fool,' she said.
She took hold of the bell-rope.
'Don't ring that bell if you value your life,' said Nella.
'If what?' Miss Spencer remarked.
'If you value your life,' said Nella calmly, and with the words she pulled from her pocket a very neat and dainty little revolver.