Very interesting - brilliant

 Boss says to secretary: For a week we will go abroad, so make arrangements.
 Secretary makes a call to Husband: For a week my boss and I will be going abroad, you look after yourself.
 Husband makes a call to secret lover: My wife is going abroad for a week, so let's spend the week together.
 Secret lover makes a call to small boy whom she is giving private tuition: I have work for a week, so you need not come for class.
 Small boy makes a call to his grandfather: Grandpa, for a week I don't have class 'coz my teacher is busy.
 Let's spend the week together.

 Grandpa (the 1st boss;) ) makes a call to his secretary:
 This week I am spending my time with my grandson. We cannot attend that meeting.
 Secretary makes a call to her husband: This week my boss has some work, we cancelled our trip.
 Husband makes a call to secret lover: We cannot spend this week together, my wife has cancelled her trip.
 Secret lover makes a call to small boy whom she is giving private tuition: This week we will have class as usual.
 Small boy makes a call to his grandfather: Grandpa, my teacher said this week I have to attend class. Sorry I can't give you company.
Grandpa makes a call to his secretary: Don't worry this week we will attend that meeting, so make arrangements. 

 Now This is call dead Lock!!!!!!!!