Warning:Spoilers appropriate up to and including Waters of Mars.

A/N:The title comes from a really old kids TV show that freaked out several generations. And there is a crossover with the Chronicles of Narnia if you squint.

Disclaimer: Not mine, never was, never will be.

The skeletal tree stood proud against the barren landscape, the only vegetation as far as the eye could see. It was long dead, but it lingered as a reminder that this desolate highland place once teemed with life.

It was hard to imagine now, but the rocks it grew out of were once a road. The road had run straight and true and had been the royal highway for a once noble and now lost civilisation.

In those days, the tree had been planted at a crossroads in an act of symbolism that was repeated the universe over. Once it had grown tall and strong, it was used to hang condemned criminals.

For centuries the enemies of the House of Jadis were hung from its branches and folklore said that the souls of the condemned were absorbed into the roots of the tree, feeding it. The Doctor didn't believe that, but it was true that the tree had died just a few months after the hangings ceased.

Legend had it that the tree was possessed by those who had died on its boughs and that it would sing a lament for the dead to one who had lost everything. The Doctor hoped that part was true.

He had brought Tegan the first time, hoping she might find some measure of healing in that place. They talked for hours, sitting in the shadow of the tree, in a way they had not before and never would again. When the sun set they returned to the TARDIS but the tree did not sing that day.

When he brought Rose there, they picnicked beneath its boughs and Rose commented that it reminded her of Scotland. The Doctor smiled and agreed and decided he'd take her to Scotland one day, show her Jamie's Highlands, but first he really needed to take her to a great gig. The tree did not sing that day, but the Doctor did not expect it to.

The third visit was not of his choosing. TARDIS delivered him blinking into the sunlight of that world after he had lost Rose. He didn't want to go to the tree this time; he didn't want to hear it sing anymore. So he wandered around for a while, and he found a great, ruined city that seemed to belong to a race of giants.

He explored the ruins and examined the remains of the civilisation he found there, but when nothing had happened for several hours, he wandered back to the TARDIS and left.

*-*

He stood beneath the tree and looked up into its branches, taking in every familiar twig and knot. He had lost so much: Rose, the Master, Donna, his entire planet. Surely no other in the universe had lost as much as him?

"Well, come on then! What are you waiting for? I'm on a clock here and it's finally ticking, so if you're ever going to sing it needs to be now," he called out, walking around the trunk as he did so. He stopped and waited with baited breath. The tree was bathed in red light from the huge and dying star that was this planet's sun and it seemed suddenly ominous. Strangely suddenly afraid, the Doctor turned his back on the tree and began to walk away.

He had taken only a few steps when a breeze picked up and as it passed through the branches of the tree the Doctor thought he heard whispers. He turned back and listened, and the tree sang.