<?xml version="1.0" encoding="us-ascii"?><InstanceReport xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"><Version>2.4.0.8</Version><ReportLongName>0019 - Disclosure - 13. SUBSEQUENT EVENTS</ReportLongName><DisplayLabelColumn>true</DisplayLabelColumn><ShowElementNames>false</ShowElementNames><RoundingOption /><HasEmbeddedReports>false</HasEmbeddedReports><Columns><Column FlagID="0"><Id>1</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><CurrencyCode /><FootnoteIndexer /><hasSegments>false</hasSegments><hasScenarios>false</hasScenarios><MCU><KeyName /><CurrencySymbol /><contextRef><ContextID>From2012-12-01to2013-05-31</ContextID><EntitySchema>http://www.sec.gov/CIK</EntitySchema><EntityValue>0001436549</EntityValue><PeriodDisplayName /><PeriodType>duration</PeriodType><PeriodStartDate>2012-12-01T00:00:00</PeriodStartDate><PeriodEndDate>2013-05-31T00:00:00</PeriodEndDate><Segments /><Scenarios /></contextRef><UPS /><CurrencyCode /><OriginalCurrencyCode /></MCU><CurrencySymbol /><Labels><Label Key="CalendarSupplement" Id="0" Label="6 Months Ended" /><Label Key="Calendar" Id="1" Label="May 31, 2013" /></Labels></Column></Columns><Rows><Row FlagID="0"><Id>1</Id><IsAbstractGroupTitle>true</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>1</Level><ElementName>us-gaap_SubsequentEventsAbstract</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText /><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>xbrli:stringItemType</ElementDataType><SimpleDataType>string</SimpleDataType><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>Subsequent Events [Abstract]</Label></Row><Row FlagID="0"><Id>2</Id><IsAbstractGroupTitle>false</IsAbstractGroupTitle><LabelSeparator>

</LabelSeparator><Level>2</Level><ElementName>us-gaap_SubsequentEventsTextBlock</ElementName><ElementPrefix>us-gaap_</ElementPrefix><IsBaseElement>true</IsBaseElement><BalanceType>na</BalanceType><PeriodType>duration</PeriodType><IsReportTitle>false</IsReportTitle><IsSegmentTitle>false</IsSegmentTitle><IsCalendarTitle>false</IsCalendarTitle><IsEquityPrevioslyReportedAsRow>false</IsEquityPrevioslyReportedAsRow><IsEquityAdjustmentRow>false</IsEquityAdjustmentRow><IsBeginningBalance>false</IsBeginningBalance><IsEndingBalance>false</IsEndingBalance><IsReverseSign>false</IsReverseSign><FootnoteIndexer /><Cells><Cell FlagID="0" ContextID="From2012-12-01to2013-05-31" UnitID=""><Id>1</Id><IsNumeric>false</IsNumeric><IsRatio>false</IsRatio><DisplayZeroAsNone>false</DisplayZeroAsNone><NumericAmount>0</NumericAmount><RoundedNumericAmount>0</RoundedNumericAmount><NonNumbericText>&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 20pt"&gt;&lt;b&gt;NOTE 13 - SUBSEQUENT EVENTS&lt;/b&gt;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 45pt"&gt;The Company has performed an evaluation
of subsequent events through July&amp;#160;12,&amp;#160;2013, and has determined there have been no material subsequent events requiring
disclosure.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 45pt"&gt;On July 12, 2013, Methes
Canada entered into a Term Loan Facility Agreement with 1730636 Ontario Limited (the &amp;#147;Agreement&amp;#148;) pursuant to which
Methes Canada may borrow up to $1,536,000 (CDN$1,600,000) for a term of 12 months at an interest rate of 12% per annum. Under
the terms of the Agreement, interest is payable monthly and outstanding principal is due at maturity. Outstanding principal
would be prepayable after six months upon 30 days&amp;#146; notice and payment of a penalty equal to one-month's interest. Upon
closing, the facility  will be collateralized by a security agreement from Methes Canada on certain of its assets and a first
collateral mortgage on its real property located at Sombra, Ontario.&amp;#160;&amp;#160;The facility prohibits payment of debt owed
by the Company to certain of its stockholders and a director during the life of the facility and contains other customary
debt covenants.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 45pt"&gt;The proceeds from this loan will be used
to repay the short-term loan of $1,446,750 (historical amount of CDN$1,500,000), as disclosed in Note 6.&lt;/p&gt;

&lt;p style="font: 8pt/normal Times New Roman, Times, Serif; margin: 0; text-indent: 0.5in"&gt;&amp;#160;&lt;/p&gt;

&lt;p style="font: 8pt/115% Times New Roman, Times, Serif; margin: 0 0 10pt"&gt;&amp;#160;&lt;/p&gt;</NonNumbericText><FootnoteIndexer /><CurrencyCode /><CurrencySymbol /><IsIndependantCurrency>false</IsIndependantCurrency><ShowCurrencySymbol>false</ShowCurrencySymbol><DisplayDateInUSFormat>false</DisplayDateInUSFormat></Cell></Cells><ElementDataType>nonnum:textBlockItemType</ElementDataType><SimpleDataType>na</SimpleDataType><ElementDefenition>The entire disclosure for significant events or transactions that occurred after the balance sheet date through the date the financial statements were issued or the date the financial statements were available to be issued. Examples include: the sale of a capital stock issue, purchase of a business, settlement of litigation, catastrophic loss, significant foreign exchange rate changes, loans to insiders or affiliates, and transactions not in the ordinary course of business.</ElementDefenition><ElementReferences>No definition available.</ElementReferences><IsTotalLabel>false</IsTotalLabel><UnitID>0</UnitID><Label>13. SUBSEQUENT EVENTS</Label></Row></Rows><Footnotes /><IsEquityReport>false</IsEquityReport><ReportName>13. SUBSEQUENT EVENTS</ReportName><MonetaryRoundingLevel>UnKnown</MonetaryRoundingLevel><SharesRoundingLevel>UnKnown</SharesRoundingLevel><PerShareRoundingLevel>UnKnown</PerShareRoundingLevel><ExchangeRateRoundingLevel>UnKnown</ExchangeRateRoundingLevel><HasCustomUnits>true</HasCustomUnits><IsEmbedReport>false</IsEmbedReport><IsMultiCurrency>false</IsMultiCurrency><ReportType>Sheet</ReportType><RoleURI>http://methes.com/role/SubsequentEvents</RoleURI><NumberOfCols>1</NumberOfCols><NumberOfRows>2</NumberOfRows></InstanceReport>
