Right hip definitely not all it should be, but still two days' walk to the nearest re-supply point, so no peace for the wicked just yet. Press on painfully as far as Hartmannswillerkopf, another preserved First World War battlefield - this time, avoiding barbed wire.
Meet an old Frenchman meditating outside a bunker. He points: "That's where my Dad was captured in 1915." Sit enthralled as he recounts his father's exploits, then his own at the time he went on the run to avoid Wehrmacht conscription in 1944. Living history.
Sleep in a field which overlooks Alsace with a view that reaches 200 miles to the Austrian Alps. Wonder why the farmer grins so much ...
Woken at 5.30am by heavy breathing. Pull tent open, find myself eyeball to eyeball with the largest bull in Christendom. He promptly tries to join me. Saved from death by crushing by a twanging guy-rope which alarms him into retreating.
Pack in record time and walk nonchalantly away with half a ton of curious beef breathing down my neck. Then meet the grinning farmer, who invites me to breakfast, having had his little joke. I resist the temptation to brain him with the brioche.
Reach Thann, a village famous for its 14th-century church, housing the finest carved choir-stalls in the whole of Europe. It's closed, owing to recent vandalism.
Look piteous and say, but I walked here ... Guard says "you're mad", and lets me in.
Wonderful representations of such noted religious themes as the Little Man in Spectacles, the Sleepy Student and Two Monkeys Arguing. Reverent stuff.
Forecast predicts two more days' fine weather, then storms. Push on for Belfort, the end of the Vosges. Unwise. Flat walking is okay, but the climbing hurts; starting to wonder if I'll ever manage the Alps.
Drop down into the woods of the Belfort Gap at last. Look back, see the mountains engulfed in storms. Smile smugly. Big mistake. Sky turns black, gale erupts out of nowhere. Branches crash to earth. Thunder explodes overhead. Bolt for cover, shelter in terror under Office National des Forets sign-board as trees fall all around.
Storm stops with theatrical suddenness. Sun illuminates a battered sign - "Storm danger. Keep out." Now they bloody tell me.
Finally reach Belfort late in evening. Hotels, hot showers, clean sheets. An earthly paradise. But it's decision time. The hip's in no fit state to tackle the Alps. Sadly, from here I'll have to turn westwards towards the Rhone and flat country. And so Burgundy, Beaune, Chateauneuf ... life's hard being a pilgrim.
For more information on the charity trombone walk, visit the website www.netplaycafe. co.uk/bonewalk