The Ministry of Defence is not only responsible for the nation's security, but they are also one of the UK's major landowners. Charlotte and Matt have security clearance to enter their largest site, Salisbury Plain, where they find out how the MoD maintain a balance between military training, farming and conservation. Matt dons his waders and meets a team looking after a threatened and vitally important chalk river, whilst Charlotte finds out how endangered flora and fauna survive under the wrath of heavy military vehicles. We also hear from a farmer managing his cattle around tight military training operations, and meet a passionate birder who has dedicated his life to bringing back one of the heaviest flying birds in the world to Salisbury Plain, the great bustard. And Adam is in Northern Ireland catching up with young farmer Emily McGowan to help with harvest.