0940005

We propose a 1Ms TOO observation of a bright black-hole transient either known or unknown to follow its complete transition from hard to soft state. This transition which takes place at high flux levels encompasses marked changes in the properties of the accretion flow and it includes the time at which the ejection of an accelerating relativistic jet stops abruptly. The study of the high-energy properties during the transition is important for our understanding of accretion onto black holes and can only be accomplished with INTEGRAL. A simultaneous large multi-wavelength campaign is being organized to support the proposed observation including other X-ray satellites. The campaign will be centered around the INTEGRAL pointing. The trigger will be provided by a threshold limit in either hard or soft X-ray flux. Such a monitoring is becoming a key goal in the community working on black-hole binaries. [truncated! Please see actual data for full text]