Objection filing

Plaintiff has sent a notice summons to Defendant 1 and Defendant 2 (Myself)

The case is actually between Plaintiff and the Defendant 1.

Defendant 1 has stated all wrong facts in the written suit, due to his written statement I as Defendant 2 have major loss in the property.

Now I as Defendant 2 have varying and actual facts which benefit all. My lawyer is asking to file a different petition/suit. 

Is a different petition or suit required?