against any of the respondents ought reasonably to have been
discovered by the appellants more than two years before they
moved to join the respondents as defendants to the action.
 I would therefore allow the appeal, grant leave to the appellants to add the respondents as defendants to the action and
permit the respondents to plead the expiry of a limitation period
in their defence.
 The appellants started their action on June 24, 2013, claim-
ing that the defendant Dr. Barzo was negligent in his treatment
of Mr. Morrison. The essence of the claim is that on June 23,
2011, during a chiropractic treatment, Dr. Barzo forcefully
“twisted” Mr. Morrison’s spine, causing a lumbar disc protrusion
and cauda equina syndrome (“CES”). Mr. Morrison was diag-
nosed with CES on July 14, 2011 and required emergency surgery
the next day.
 Dr. Barzo’s statement of defence was delivered on May 6,
2014. On May 13, 2014, he third partied two of the three
respondents: Cristina Edwards, a registered massage therapist,
and Charles Murphy, a family doctor. The third party claim
asserts that Mr. Morrison’s alleged lumbar disc injury and CES
resulted from circumstances occurring subsequent to the June
28, 2011 chiropractic treatment. It also asserts that both third
parties were negligent in their treatment of Mr. Morrison
between the date of the chiropractic treatment and the referral
on July 14 for emergency surgery.
 The third parties defended the main action and the third
party claim. Examinations for discovery took place in May and
 On May 11, 2016, and just less than two years after the
third party claim was issued, the appellants moved to add as
defendants to the action, Ms. Edwards, Dr. Murphy, as well as
Susan Boulanger, a nurse practitioner in Dr. Murphy’s medical
office. The draft amended statement of claim alleges that certain
acts and omissions of the respondents between the date of the chiropractic treatment and when Mr. Morrison received emergency
surgery were negligent. The allegations against Ms. Edwards and
Dr. Murphy track the allegations set out in Dr. Barzo’s third party
claim. The allegations against nurse-practitioner Ms. Boulanger
are in essence that she neglected to respond in a timely way to
Mr. Morrison’s complaints with referrals and diagnostic tests.
 The appellants’ motion was supported by an affidavit of
their counsel, Ms. Oakley. The affidavit explained that it was not
until certain information was provided at the examinations for