Since Ynys had known she was with child, this visionariness had been intensified, this longing had become more and more a deep need. Even with Alan she felt at times the intrusion of an alien influence. If in her body was a mystery, a mystery also was in her brain and in her heart.
Alan knew this, and knowing, understood. It was for gladness to him that Ynys should do as she would; that in these long hours of solitude she drank deep of the elixir of peace; and that this way of happiness was open to her as to him. Never did these isolations come between them; indeed they were sometimes more at one then than when they were together, for all the deep happiness which sustained both upon the strong waters of their love.
So, when Alan heard from Kirsten that Ynys had sailed westward, he was in no way alarmed. But when the sun had set, and over the faint blue film of the Isle of Tiree the moon had risen, and still no sign of Ynys, he became restless and uneasy. Kirsten begged him in vain to eat of the supper she had prepared. Idly he moved to and fro along the rocky ledge, or down by the pebbly shore, or across the green airidh; eager for a glimpse of her whom he loved so passing well.
At last, unable longer to endure a growing anxiety, he put out in his boat, and sailed swiftly before the slight easterly breeze which had prevailed since moonrise. So far as Aoidhu, all the way from Aonaig, there was not a haven anywhere, nor even one of the sea caverns which honeycombed the isle beyond the headland. A glance, therefore, showed him that Ynys had not yet come back that way. It was possible, though unlikely, that she had sailed right round Rona; unlikely because in the narrow straits to the north, between Rona and the scattered islets known as the Innse-mhara, strong currents prevailed, and particularly at the full of the tide, when they swept north-eastward, dark and swift as a mill-race.
Once the headland was passed and the sheer precipitous westward cliffs loomed black out of the sea, he became more and more uneasy. As yet, there was no danger; but he saw that a swell was moving out of the west, and whenever the wind blew that way the sea arcades were filled with a lifting, perilous wave, and escape from them was difficult and often impossible. Out of the score or more great corridors which opened between Aoidhu and Ardgorm, it was difficult to know into which to hazard entry in quest of Ynys. Together they had examined all of them. Some twisted but slightly; others wound sinuously till the green, serpentine alleys, flanked by basalt walls hundreds of feet high, lost themselves in an indistinguishable maze.
But that which was safest, and wherein a boat could most easily make its way against wind or tide, was the huge, cavernous corridor known locally as the Uamh-nan-roin, the Cave of the Seals.
For this opening Alan steered his boat. Soon he was within the wide corridor. Like the great cave at Staffa, it was wrought as an aisle in some natural cathedral; the rocks, too, were fluted columnarly and rose in flawless symmetry as though graven by the hand of man. At the far end of this gigantic aisle, there diverges a long, narrow arcade, filled by day with the green shine of the water, and by night, when the moon is up, with a pale froth of light. It is one of the few where there are open gateways for the sea and the wandering light, and, by its spherical shape, almost the only safe passage in a season of heavy wind. Half-way along this arched arcade a corridor leads to a round cup-like cavern, midway in which stands a huge mass of black basalt, in shape suggestive of a titanic altar. Thus it must have impressed the imagination of the islanders of old, for by them, even in a remote day, it was called Teampull-nan-Mhara, the Temple of the Sea. Owing to the narrowness of the corridor, and to the smooth, unbroken walls which rise sheer from the green depths into an invisible darkness, the Strait of the Temple is not one wherein to linger long, save in a time of calm.
Instinctively, however, Alan quietly headed his boat along this narrow way. When, silently, he emerged from the arcade, he could just discern the mass of basalt at the far end of the cavern. But there, seated in her boat, was Ynys; apparently idly adrift, for one oar floated in the water alongside, and the other suspended listlessly from the tholes.
His heart had a suffocating grip as he saw her whom he had come to seek. Why that absolute stillness, that strange, listless indifference? For a dreadful moment he feared that death had indeed come to her in that lonely place where, as an ancient legend had it, a woman of old time had perished, and ever since had wrought death upon any who came thither solitary and unhappy.
But at the striking of the shaft of his oar against a ledge, Ynys gave a low cry and looked at him with startled eyes. Half rising from where she crouched in the stern, she called to him in a voice that had in it something strangely unfamiliar.