Our trombone-playing pilgrim doesn't get around to busking this week, but does meet a woman for whom he climbs a mountain

1 August

Farewell to the mountains, but what a parting! A 10-mile ridge dropping from more than 5,000ft to 3,000ft, flanked by deep valleys, it's like crossing the roof of France. Other walkers pass me: two Belgians, a Breton, the Parisian Gays' Outdoor Club. Everyone stops to chat, offers food and encouragement.

Finally reach Murat, a cluster of stone houses unchanged since the 16th century. Welcomed at its priory by the toughest-looking friar with the biggest grin I've ever seen: Brother Ghislain, priest, ex-Para, Santiago veteran. Spend all evening chatting. His parting gift: a kilo of chocolate and an icon of the Virgin Mary. Cared for, body and soul...

2 August

Climb out of Murat. Above the town, a beautiful girl. Our eyes meet. Our hearts beat fast! Flushed cheeks, heavy breathing, can this be love? No, the effect of a one-in-three climb, but we chat anyway. She's making for the mountains. I'm jealous. She's good company, so I join her. Back up another ridge to the Plomb du Cantal, 6,000ft - completely the wrong direction, but who cares?

Other walkers join us. All start chatting. On the second-highest peak in central France, we argue about the cabalistic subtext of Romanesque ecclesiastical architecture. It seems a logical topic at the time.

3-6 August

East to Le Puy-en-Velay, traditional start of the Santiago trail, my half-way point. (Logical again.) River-valleys and wooded hills, dotted with tiny villages of volcanic stone - beautiful, but hard work in the heat.

Battle on to my last campsite, eight miles from Le Puy, drop rucksack, sigh with relief - and all goes dark. Turn round. Black clouds boil from horizon to horizon. Lightning stabs the hills, races towards me. Terrifying. Exhilarating. Don't think I'll be camping, then...

Pack up, and bolt. Too slow. Clouds catch me after a mile. It's like night falling. Thunder starts two miles later. Rain follows. Deluge! Horizon disappears. Road becomes a river. Cars crawl by. Raindrops bounce knee- high.

Suddenly, curtains part and I see Le Puy's jet-black spires, perched on rock pinnacles, framed by a barrage of lightning. Incredible. Sing my way into town. Above me, the cathedral: ancient and immense, tourists cowering under its colossal portal. Lightning explodes overhead as I climb the streaming cobbled steps. Tourists watch curiously. Half way! An incredible moment. Victory. Relief. Triumph!

But also a touch of sadness. Realise for the first time that this will end one day. Best make the most of it, then...

For more information on the charity trombone walk, visit the website at www.netplaycafe.co.uk/bonewalk