Mary had close ties with France – it was while her unit was on the Somme in 1916 that she met Captain Edward Louis Spears, a British liaison officer attached to the French army. He was subsequently promoted to a General Staff Officer 1st Grade, liaising between the French Ministry of War and the War Office in London. They were married in 1918 and living in Paris at the end of the war. Spears later became a Member of Parliament; his pro-French views in the Commons earning him the nickname of 'the Member for Paris'. They had a wide circle of influential friends, both British and French, whom they entertained at their London home during the inter-war period. Mary Borden (Mrs Spears) agreed to be in charge of the (largely British) female personnel – the nurses and drivers of Lady Hadfield's new field hospital with its 100 beds. Mary Spears was generally known as 'Madame la Générale' by the French – a reference to her husband's rank in the British army. The French military 'Service de Santé' agreed to provide the male staff for the medical unit, including doctors, orderlies and drivers for the unit's heavy trucks. Complete with tents, X-ray equipment, sterilizing apparatus, surgical instruments, beds, bedding, linen and ward equipment, the Hadfield-Spears mobile hospital left Paris in February 1940 for the village of St Jean le Bassel, near the front line in Lorraine. The medical officer in charge was Le Médecin Capitaine Jean Gosset – under him were three young French surgeons, a radiographer and administrative staff. There were 12 French drivers for the heavy trucks and 50 private soldiers. The British girls consisted of ten nurses, and 15 drivers of the Mechanised Transport Corps (MTC). Lady Hadfield had donated a Renault limousine for the use of Mrs Spears. The Hadfield-Spears unit was attached to the French 4th Army, which was commanded by Général Réquin, a former World War 1 comrade of General Spears. At St Jean le Bassel, they were billeted partly at a convent and partly in the village itself. Their predecessors had left the wards in poor condition and they spent two weeks getting the place into shape before moving patients to their new quarters. There was little military activity in the sector – even when the Germans launched their attack on the Netherlands, Luxembourg and Belgium on 10 May. The girls had a peaceful time in the French countryside, making sorties up to the front line at Sarreguemines, which had become a ghost town since its French inhabitants were evacuated nine months previously.